Category Archives: Asteroids & Comets

Space sciences roundup – June.26.2019

A sampling of recent articles, videos, and images from space-related science news items:

Asteroids:

** NASA’s OSIRIS-REx probe gets up close to asteroid Bennu : OSIRIS-REx Breaks Another Orbit Record | NASA

On June 12, NASA’s OSIRIS-REx spacecraft performed another significant navigation maneuver—breaking its own world record for the closest orbit of a planetary body by a spacecraft.

The maneuver began the mission’s new phase, known as Orbital B, and placed the spacecraft in an orbit 680 meters (2,231 feet) above the surface of asteroid Bennu. The previous record—also set by the OSIRIS-REx spacecraft—was approximately 1.3 kilometers (0.8 miles) above the surface.

Upon arrival at Bennu, the team observed particles ejecting into space from the asteroid’s surface. To better understand why this is occurring, the first two weeks of Orbital B will be devoted to observing these events by taking frequent images of the asteroid’s horizon. For the remaining five weeks, the spacecraft will map the entire asteroid using most of its onboard science instruments: the OSIRIS-REx Laser Altimeter (OLA) will produce a full terrain map; PolyCam will form a high-resolution, global image mosaic; and the OSIRIS-REx Thermal Emission Spectrometer (OTES) and the REgolith X-ray Imaging Spectrometer (REXIS) will produce global maps in the infrared and X-ray bands. All of these measurements are essential for selecting the best sample collection site on Bennu’s surface.

Data from these surface studies will be used to find the optimum spot to set down and take a sample to take back to Earth.

The OSIRIS-REx spacecraft is on a seven-year journey to study the asteroid Bennu and return a sample from its surface to Earth. This sample of a primitive asteroid will help scientists understand the formation of the Solar System over 4.5 billion years ago. Sample collection is scheduled for summer of 2020, and the spacecraft will deliver the sample to Earth in September 2023.

An artist's view of OSIRIS-REx investigating asteroid Bennu
“On Jun. 12, 2019, NASA’s OSIRIS-REx spacecraft went into orbit around asteroid Bennu for a second time — breaking its own record for the closest orbit of a planetary body by any spacecraft.” Artwork credits: University of Arizona

** Japan’s Hayabusa2 probe may touch down on asteroid Ryugu again: Approach to the 2nd touchdown – Part 1: observations near the touchdown point – JAXA Hayabusa2 project

Our first touchdown took place this year on February 22. Then as a new challenge for the Hayabusa2 Project, we succeeded in creating an artificial crater using the Small Carry-on Impactor (SCI) on April 5. The last big operation left at asteroid Ryugu is the collection of subsurface material exposed with the creation of the artificial crater. In order to collect this material, we need a second touchdown for which the project has been steadily preparing. At this point, it has not yet been decided whether or not to go ahead with a second touchdown, but here we will introduce our preparations in the “Approach to the second touchdown”.

After the operation to form the artificial crater, the spacecraft descended a total of four times above or near the crater site. These descent operations allowed us to obtain detailed data of the region near the artificial crater. In addition, we succeeded in dropping a target marker in the area close to the artificial crater on May 30. Combined, these operations mean that the situation around the artificial crater is now well understood.

The rocky surface, however, makes it difficult to find a safe spot to set down.

As you can see in [the figure below], asteroid Ryugu is covered with boulders. If we go for a second touchdown, we need to aim for a point close to the target marker which has no obstacles. The project is currently examining this area in detail.

Image of Ryugu surface
“Image taken on June 13, 2019 during the operation PPTD-TM1B. This is a composite of 28 images taken at 7 second intervals starting from 10:58 JST (upper left) to 11:01 (lower right) using the Optical Navigation Camera – Telescopic (ONC-T). The image altitude is about 52m at the start and 108m at the end. The white point in the upper-left center is the target marker. You can see that detailed images have been acquired continuously from the target marker to the edge of the artificial crater, located in the lower-right of the image. (Image credit ※: JAXA, Chiba Institute of Technology, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Meiji University, University of Aizu, AIST.) “

The Sun:

** Lunar regolith reveals secrets of the early sun: Moon Samples Help Scientists Study Ancient Sun | NASA

Saxena incorporated the mathematical relationship between a star’s rotation rate and its flare activity. This insight was derived by scientists who studied the activity of thousands of stars discovered by NASA’s Kepler space telescope: The faster a star spins, they found, the more violent its ejections. “As you learn about other stars and planets, especially stars like our Sun, you start to get a bigger picture of how the Sun evolved over time,” Saxena said.  

Using sophisticated computer models, Saxena, Killen and colleagues think they may have finally solved both mysteries. Their computer simulations, which they described on May 3 in the The Astrophysical Journal Letters, show that the early Sun rotated slower than 50% of baby stars. According to their estimates, within its first billion years, the Sun took at least 9 to 10 days to complete one rotation.  

They determined this by simulating the evolution of our solar system under a slow, medium, and then a fast-rotating star. And they found that just one version — the slow-rotating star — was able to blast the right amount of charged particles into the Moon’s surface to knock enough sodium and potassium into space over time to leave the amounts we see in Moon rocks today.   

“Space weather was probably one of the major influences for how all the planets of the solar system evolved,” Saxena said, “so any study of habitability of planets needs to consider it.” 

Jupiter:

**  More wonderful views of Jupiter created by citizen scientists from Juno’s raw imagery: Tumultuous Clouds of Jupiter | Mission Juno/Kevin M. Gill

This stunning compilation image of Jupiter’s stormy northern hemisphere was captured by NASA’s Juno spacecraft as it performed a close pass of the gas giant planet. Some bright-white clouds can be seen popping up to high altitudes on the right side of Jupiter’s disk. (The Juno team frequently refers to clouds like these as “pop-up” clouds in image captions.)

Juno took the four images used to produce this color-enhanced view on May 29, 2019, between 12:52 a.m. PDT (3:52 a.m. EDT) and 1:03 a.m. PDT (4:03 a.m. EDT), as the spacecraft performed its 20th science pass of Jupiter. At the time the images were taken, the spacecraft was between 11,600 miles (18,600 kilometers) and 5,400 miles (8,600 kilometers) above Jupiter’s cloud tops, above a northern latitude spanning from about 59 to 34 degrees.

Citizen scientist Kevin M. Gill created this image using data from the spacecraft’s JunoCam imager.

Tumultuous Clouds of Jupiter
“Tumultuous Clouds of Jupiter” – Credits NASA/JPL-Caltech/SwRI/MSSS with image processing by Kevin M. Gill.

Gill also made this overflight of Jupiter’s Great Red Spot:

And Gerald Eichstädt made this terrific time-lapsed tour of Jupiter: Juno’s Perijove-20 Jupiter Flyby, Reconstructed in 125-Fold Time-Lapse – Credit: NASA / JPL / SwRI / MSSS / SPICE / Gerald Eichstädt ©

On May 29, 2019, NASA’s Juno probe successfully performed her Perijove-20 Jupiter flyby. The movie is a reconstruction of the 2 hours and 30 minutes between 2019-05-29T07:20:00.000 and 2019-05-29T09:50:00.000 in 125-fold time-lapse. It is based on 32 of the JunoCam images taken, and on spacecraft trajectory data provided via SPICE kernel files.

In steps of five real-time seconds, one still images of the movie has been rendered from at least one suitable raw image. This resulted in short scenes, usually of a few seconds. Playing with 25 images per second results in 125-fold time-lapse. Resulting overlapping scenes have been blended using the ffmpeg tool. In natural colors, Jupiter looks pretty pale. Therefore, the still images are approximately illumination-adusted, i.e. almost flattened, and consecutively gamma-stretched to the 4th power of radiometric values, in order to enhance contrast and color.

Mars:

** Curiosity detects a curious burst in methane levels: Curiosity Detects Unusually High Methane Levels – NASA JPL

On June 23rd, the Curiosity team reported that during the previous week the

… Mars rover found a surprising result: the largest amount of methane ever measured during the mission – about 21 parts per billion units by volume (ppbv). One ppbv means that if you take a volume of air on Mars, one billionth of the volume of air is methane.

The finding came from the rover’s Sample Analysis at Mars (SAM) tunable laser spectrometer. It’s exciting because microbial life is an important source of methane on Earth, but methane can also be created through interactions between rocks and water.

Curiosity doesn’t have instruments that can definitively say what the source of the methane is, or even if it’s coming from a local source within Gale Crater or elsewhere on the planet.

On June 24th, the team reported results from a

… follow-on methane experiment this past weekend. The results came down early Monday morning: The methane levels have sharply decreased, with less than 1 part per billion by volume detected. That’s a value close to the background levels Curiosity sees all the time.

The finding suggests last week’s methane detection – the largest amount of the gas Curiosity has ever found – was one of the transient methane plumes that have been observed in the past. While scientists have observed the background levels rise and fall seasonally, they haven’t found a pattern in the occurrence of these transient plumes.

“The methane mystery continues,” said Ashwin Vasavada, Curiosity’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “We’re more motivated than ever to keep measuring and put our brains together to figure out how methane behaves in the Martian atmosphere.”

** Curiosity’s travels via Leonard David:

  • Curiosity Mars Rover: Eying Teal Ridge Outcrop – June.25.2019

    “Curiosity is still perched on top of Teal Ridge to investigate a fascinating outcrop that caps the ridge,” reports Kristen Bennett, a planetary geologist at the USGS in Flagstaff, Arizona.Scientists have been characterizing the ridge-capping material, but also devoting time to use the Sample Analysis at Mars (SAM) Instrument Suite to look for methane.

MAHLI-Sol-2444-June-22-2019
“Curiosity Mars Hand Lens Imager (MAHLI) image produced on Sol 2444, June 22, 2019. Credit: NASA/JPL-Caltech/MSSS.” Larger image
  • Curiosity Mars Rover: Ridge Work – June.20.2019

    NASA’s Curiosity Mars rover is now carrying out Sol 2442 duties, parked on Teal Ridge, in the midst of an extended contact science campaign.At this ridge location, new imagery from the robot shows crossbedding in a bedrock layer, as well as a contact between the bedrock outcrop and a rubbly layer below.

Curiosity Navcam - Sol-2442-June-20-2019
A view from Teal Ridge taken by Curiosity’s Navcam – Sol-2442-June-20-2019
“Curiosity Navcam Left B image taken on Sol 2439, June 17, 2019. Credit: NASA/JPL-Caltech.” Larger image.

** Bob Zimmerman reports on interesting Mars images taken from orbit:

  • Strange Martian gullies – June.21.2019 – Bob finds the gullies in the image “Older Gullies and Channels” below fascinating –

    … because they appear to be some form of erosion drainage coming down both sides of a high ridge near the northern rim of this large apparently unnamed crater in the southern cratered highlands of Mars, to the west of Hellas Basin.On Earth my immediate explanation for this erosion would be a major monsoon-like storm, such as we get here in the southwest and call “gully-washers.” When a lot of water is quickly dumped onto a hill where there is not of vegetation to help bind the soil together, the water will quickly carve out gullies that looks almost exactly like these.

Older Gullies and Channels in Slopes of Softened Large Crater
Older Gullies and Channels in Slopes of Softened Large Crater – HiRISE

On Mars, who knows? It certainly wasn’t a monsoon thunderstorm that did this. And being in the Martian southern highlands it is unlikely it was from an ocean of any kind. Were there lakes here? Past research has found places where lakes might have existed on Mars, but these places are far north in the transitional zone into the northern lowlands.

  • Mass wasting on Mars – June.19.2019Mass wasting is a term that geologists use to describe a specific kind of avalanche, where the material moves down slope suddenly in a single mass.The image [below], taken from the image archive of the high resolution camera on Mars Reconnaissance Orbiter (MRO) and cropped and reduced in resolution to post here, shows a dramatic example of this kind of avalanche. You can see two separate avalanches, each of which moved a significant blob of material down slope into the center of the crater floor.

  • Wind and/or water erosion on the Martian northern lowlands – June.17.2019The picture [below], cropped and reduced in resolution to show here, was taken by the high resolution camera on Mars Reconnaissance Orbiter on April 21, 2019, and shows the erosion process produced by either wind or water as it flowed from the east to the west past one small mesa.It is almost certain that the erosion here was caused by wind, but as we don’t know when this happened, it could also be very old, and have occurred when this terrain was at the bottom of the theorized intermittent ocean that some believe once existed on these northern lowlands. The location itself, near the resurgences for Marineris Valles and the other drainages coming down from the giant volcanoes, might add weight to a water cause, except that the erosional flow went from east to west, and the resurgences were coming from the opposite direction, the west and the south.
Topographic Interactions in Vastitas Borealis
Topographic Interactions in Vastitas Borealis. HiRISE at U. of Arizona.

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I Was a Teenage Space Reporter:
From Apollo 11 to Our Future in Space

Space sciences roundup – June.13.2019

A sampling of recent articles, videos, and images from space-related science news items:

** ESA-led Heracles mission will return samples of the lunar surface to Earth: Landing on the Moon and returning home: Heracles – ESA

The Heracles lander will target a previously unexplored region near the lunar South Pole as an interesting area for researchers. A lander with a rover inside and ascent module on top will land there. Monitored and controlled from the lunar Gateway, the rover will scout the terrain in preparation for the future arrival of astronauts, and collect samples. The ascent module will take off from the surface and fly to the Gateway with the samples taken by the rover.

When the ascent module carrying the sample container arrives, the Gateway’s robotic arm will capture it and extract the sample container. The sample container will be received by the astronauts via a science airlock and pack it in NASA’s Orion spacecraft that is powered by the European Service Module. Orion will fly to Earth with astronauts and land with the Heracles lunar samples for analysis in the best laboratories on Earth.

** Massive metal deposit may underlie the Moon’s South Pole–Aitken basin: Mass Anomaly Detected Under the Moon’s Largest Crater – Baylor University

A mysterious large mass of material has been discovered beneath the largest crater in our solar system — the Moon’s South Pole-Aitken basin — and may contain metal from an asteroid that crashed into the Moon and formed the crater, according to a Baylor University study.

“Imagine taking a pile of metal five times larger than the Big Island of Hawaii and burying it underground. That’s roughly how much unexpected mass we detected,” said lead author Peter B. James, Ph.D., assistant professor of planetary geophysics in Baylor’s College of Arts & Sciences.

The crater itself is oval-shaped, as wide as 2,000 kilometers — roughly the distance between Waco, Texas, and Washington, D.C. — and several miles deep. Despite its size, it cannot be seen from Earth because it is on the far side of the Moon.

Dennis Wingo has long claimed that asteroid impacts on the Moon have enriched it with vast quantities of valuable metals.

Many other space scientists have claimed that the materials of such bodies were vaporized on impact and thinly spread over the Moon and thus not accessible by standard mining techniques.

** The Psyche mission will study a metallic asteroid up close :  NASA’s Psyche Mission Has a Metal World in Its Sights – NASA

Designed to explore a metal asteroid that could be the heart of a planet, the Psyche mission is readying for a 2022 launch. After extensive review, NASA Headquarters in Washington has approved the mission to begin the final design and fabrication phase, otherwise known as Phase C. This is when the Psyche team finalizes the system design, develops detailed plans and procedures for the spacecraft and science mission, and completes both assembly and testing of the spacecraft and its subsystems.

“The Psyche team is not only elated that we have the go-ahead for Phase C, more importantly we are ready,” said Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe. “With the transition into this new mission phase, we are one big step closer to uncovering the secrets of Psyche, a giant mysterious metallic asteroid, and that means the world to us.”

The mission still has three more phases to clear. Phase D, which will begin sometime in early 2021, includes final spacecraft assembly and testing, along with the August 2022 launch. Phase E, which begins soon after Psyche hits the vacuum of space, covers the mission’s deep-space operations and science collection. Finally, Phase F occurs after the mission has completed its science operations; it includes both decommissioning the spacecraft and archiving engineering and science data.

The Psyche spacecraft will arrive at Asteroid Psyche on Jan. 31, 2026, after flying by Mars in 2023.

The mission will also test laser communications with deep space probes:

Deep Space Optical Communications (DSOC)
Diagram of tests of the Deep Space Optical Communications (DSOC) package on the Psyche spacecraft.

** A review of the Hayabusa2 mission to the Ryugu asteroid, since its arrival in June of 2018: Treasure Hunting With Hayabusa2 – The Planetary Society

So far, multiple devices have been placed on the surface and an explosive was set off as well. A prime goal of the mission is to return a surface sample to Earth. One sampling was made in February.

Hayabusa2 Touchdown
Sampling Ryugu: “The moment that Hayabusa2 contacted asteroid Ryugu, it fired a bullet through its sampler horn (center) to knock material loose from the surface and then immediately fired its thrusters to ascend. This photo sequence, taken from an altitude of up to about 15 meters, demonstrated the success of the bullet; dark-colored fragments tumble in Hayabusa2’s shadow in the space beneath the craft.” Credits: JAXA and the Planetary Society

As this article goes to press, we are deciding whether to collect a second sample from a region close to the crater or from a second site on the asteroid. This second sample will likely be our last since by July, Ryugu will be nearing the perihelion of its orbit, and its surface will become too warm for touchdown operations.

Hayabusa2 will then continue to examine Ryugu remotely until the end of the year and return to Earth with the samples at the end of 2020. It is going to be a busy few years!

This week the spacecraft made a “Low descent observation operation“, that is, it came in close and successfully dropped a target marker on the surface of the asteroid.

Preparations for the descent began on June 11 and the descent will begin on June 12 at 11:40 JST (on-board time) with the spacecraft descending at a speed of 0.4m/s. The speed will be reduced to 0.1 m/s at 22:00 JST on the same day. The spacecraft will read an altitude of about 35m on June 13 at 10:34 JST and then begin to ascend from 10:57 JST. The schedule of the operation is shown in Figure 1. Please be aware that the actual operation time may differ as the times shown are the planned values.

Low altitude sequence
Low altitude sequence for PPTD-TM1B. Credit: JAXA.

A view of Ryugu as the spacecraft closed in on it:

Ryugu - June.13.2019
A view of Ryugu on June 13th from Hayabusa2 as it approached the surface.

To make a model of Hayabusa2, check out the JAXA paper models page.

** An update on operational science spacecraft spread throughout the solar system: Where We Are: An At-A-Glance Spacecraft Locator | The Planetary Society

Where We Are 2019-July-1
A diagram illustrating status of space science missions. Credits: Loren Roberts for The Planetary Society after a concept by Olaf Frohn

** Privately funded instrument on ESO’s VLT to search for near-by earth-like exoplanets: Breakthrough Watch and the European Southern Observatory achieve “first light” on upgraded planet-finding instrument to search for Earth-like planets in nearest star system | ESO

Newly-built planet-finding instrument installed on Very Large Telescope, Chile, begins 100-hour observation of nearby stars Alpha Centauri A and B, aiming to be first to directly image a habitable exoplanet

Breakthrough Watch, the global astronomical program looking for Earth-like planets around nearby stars, and the European Southern Observatory (ESO), Europe’s foremost intergovernmental astronomical organisation, today announced “first light” on a newly-built planet-finding instrument at ESO’s Very Large Telescope in the Atacama Desert, Chile.

The instrument, called NEAR (Near Earths in the AlphaCen Region), is designed to hunt for exoplanets in our neighbouring star system, Alpha Centauri, within the “habitable zones” of its two Sun-like stars, where water could potentially exist in liquid form. It has been developed over the last three years and was built in collaboration with the University of Uppsala in Sweden, the University of Liège in Belgium, the California Institute of Technology in the US, and Kampf Telescope Optics in Munich, Germany.

ESO’s Very Large Telescope (VLT) has recently received an upgraded addition to its suite of advanced instruments. On 21 May 2019 the newly modified instrument VISIR (VLT Imager and Spectrometer for mid-Infrared) made its first observations since being modified to aid in the search for potentially habitable planets in the Alpha Centauri system, the closest star system to Earth. This stunning image of the VLT is painted with the colours of sunset and reflected in water on the platform. While inclement weather at Cerro Paranal is unfortunate for the astronomers using it, it lets us see ESO’s flagship telescope in a new light.

More about the Watch project can be found at Breakthrough Initiatives, which is funded by Yuri Milner.

** Starshades would enable space telescopes to image earth-like exoplanets by masking out the light of their stars. NASA’s Starshade Technology Development program (ExEP) has come up with techniques for maintaining the extremely precise alignment needed between the starshade and the telescope, which will reside tens of thousands of kilometers apart: Starshade Would Take Formation Flying to Extremes | NASA.

“We can sense a change in the position of the starshade down to an inch, even over these huge distances,” Bottom said.

But detecting when the starshade is out of alignment is an entirely different proposition from actually keeping it aligned. To that end, Flinois and his colleagues developed a set of algorithms that use information provided by Bottom’s program to determine when the starshade thrusters should fire to nudge it back into position. The algorithms were created to autonomously keep the starshade aligned with the telescope for days at a time.

Combined with Bottom’s work, this shows that keeping the two spacecraft aligned is feasible using automated sensors and thruster controls. In fact, the work by Bottom and Flinois demonstrates that engineers could reasonably meet the alignment demands of an even larger starshade (in conjunction with a larger telescope), positioned up to 46,000 miles (74,000 kilometers) from the telescope.

A starshade project has not yet been approved for flight, but one could potentially join WFIRST in space in the late 2020s. Meeting the formation-flying requirement is just one step toward demonstrating that the project is feasible.

A demo of a starshade deployment:

**  Hubble images a small galaxy “furiously forming” stars : Hubble Observes Tiny Galaxy with Big Heart | ESA/Hubble

Nestled within this field of bright foreground stars lies ESO 495-21, a tiny galaxy with a big heart. ESO 495-21 may be just 3000 light-years across, but that is not stopping the galaxy from furiously forming huge numbers of stars. It may also host a supermassive black hole; this is unusual for a galaxy of its size, and may provide intriguing hints as to how galaxies form and evolve.

Nestled within this field of bright foreground stars lies ESO 495-21, a tiny galaxy with a big heart. ESO 495-21 is just 3000 light-years across, a fraction of the size of the Milky Way, but that is not stopping the galaxy from furiously forming huge numbers of stars. There are also indicators for a supermassive black hole in its centre – an unusual component for a galaxy of its size.

** Mars:

** Mars 2020 rover includes instruments for detecting signs of life: Johnson-Built Device to Help Mars 2020 Rover Search for Signs of Life | NASA

Next summer, NASA is launching the Mars 2020 robotic rover to the Red Planet, loaded with equipment to search for signs that there once was life on Mars. One device, called the Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument, will be used to detect chemicals on the Martian surface that are linked to the existence of life. To keep the instrument working well, a team from the Astromaterials Research and Exploration Science (ARES) division at NASA’s Johnson Space Center (JSC) recently built a new calibration device for the rover to check SHERLOC’s function and properly tune it during the upcoming mission.

“SHERLOC is pretty complicated, and we came up with a list of 11 things that all have to be calibrated on this instrument,” said Marc Fries, ARES planetary scientist and Mars 2020 instrument co-investigator. “This sophisticated calibration device is also going to be used for a lot of other scientific and engineering investigations, and we’re really excited that it’s JSC’s contribution to the Mars 2020 rover.”

** And Mars 2020 rover instruments will help with human missions as well: NASA’s Mars 2020 Will Blaze a Trail – for Humans – NASA JPL

When a female astronaut first sets foot on the Moon in 2024, the historic moment will represent a step toward another NASA first: eventually putting humans on Mars. NASA’s latest robotic mission to the Red Planet, Mars 2020, aims to help future astronauts brave that inhospitable landscape.

While the science goal of the Mars 2020 rover is to look for signs of ancient life – it will be the first spacecraft to collect samples of the Martian surface, caching them in tubes that could be returned to Earth on a future mission – the vehicle also includes technology that paves the way for human exploration of Mars.

** More Mars exploration with Bob Zimmerman:

*** Ghost dunes on Mars – A “Star Trek Federation” logo feature is created by winds blowing on sand dunes:

Cool image time! The Mars Reconnaissance (MRO) science team today released a captioned image of several ghost dunes on Mars. The image [below] is cropped and reduced to highlight one of those ghosts, which the scientists explain as follows.

Long ago, there were large crescent-shaped (barchan) dunes that moved across this area, and at some point, there was an eruption. The lava flowed out over the plain and around the dunes, but not over them. The lava solidified, but these dunes still stuck up like islands. However, they were still just dunes, and the wind continued to blow. Eventually, the sand piles that were the dunes migrated away, leaving these “footprints” in the lava plain.

Dune Footprints in Hellas
“These curious chevron shapes in southeast Hellas Planitia are the result of a complex story of dunes, lava, and wind.” – HiRISE at Univ. of Arizona

*** The Martian North Pole –  A tour of the many weird features of the Martian north pole area:

Since the very beginning of telescopic astronomy, the Martian poles have fascinated. Their changing sizes as the seasons progressed suggested to the early astronomers that Mars might be similar to Earth. Since the advent of the space age we have learned that no, Mars is not similar to Earth, and that its poles only resemble Earth’s in a very superficial way.

Yet, understanding the geology and seasonal evolution of the Martian poles is critical to understanding the planet itself.

Dunes Dubbed Cool Fans
Dunes Dubbed Cool Fans – HiRISE at Univ. of Arizona

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Brief Answers to the Big Questions – Stephen Hawking

Space sciences roundup – June.5.2019

A sampling of recent articles, videos, and images from space-related science news items:

[ Update: The InSight Mars lander team has come up with a plan for diagnosing and then testing a possible fix for the ground temperature probe that is stuck at a depth that is too shallow to do its job correctly: InSight’s Team Tries New Strategy to Help the ‘Mole’ | NASA

More details on the problem in this earlier report: More Testing for Mars InSight’s ‘Mole’ – NASA’s InSight Mars Lander

]

** A binary asteroid zipped past earth recently: Binary asteroids, key to Earth’s planetary defence – ESA

Humankind has had its closest look yet at a binary asteroid. As 1999 KW4 skimmed past our planet at 70 000 km/h, the most advanced visible-light telescope on Earth resolved the 1.3-km diameter asteroid and its 360-m sized moon. An even closer spacecraft-based encounter will come next decade, when NASA will send a probe to deflect the moon of the distant Didymos binary. Then ESA’s Hera mission will perform a follow-up survey right down to the body’s surface.

The International Asteroid Warning Network (IAWN) coordinated a cross-organisational observing campaign of the asteroid 1999 KW4 as it flew by Earth, reaching a minimum distance of 5.2 million km on 25 May. Since its orbit is well known, scientists were able to predict this flyby and prepare the observing campaign.

Side by side observation and artist's impression of Asteroid 199
“The unique capabilities of the SPHERE instrument on ESO’s Very Large Telescope have enabled it to obtain the sharpest images of a double asteroid as it flew by Earth on 25 May. While this double asteroid was not itself a threatening object, scientists used the opportunity to rehearse the response to a hazardous Near-Earth Object (NEO), proving that ESO’s front-line technology could be critical in planetary defence. The left-hand image shows SPHERE observations of Asteroid 1999 KW4. The angular resolution in this image is equivalent to picking out a single building in New York — from Paris. An artist’s impression of the asteroid pair is shown on the right.” – ESA

** Update on Japan’s Hayabusa2’s visit to Ryugu, a near-earth asteroid: Hayabusa2 drops second target marker, targets artificial crater for sample collection | The Planetary Society

Japan’s Hayabusa2 spacecraft has successfully dropped a second target marker on Ryugu. The reflective softball-sized sphere, which contains the names of Planetary Society members and other supporters, will give the spacecraft a visual guide if mission planners send it back to the surface to attempt a second sample collection.

JAXA is now considering collecting the sample directly from the area where Hayabusa2 created an artificial crater in early April, thanks to updated imagery collected during an aborted touchdown marker drop attempt in mid-May.

Hayabusa2 second target marker drop
“Hayabusa2 drops its second marker on asteroid Ryugu from an altitude of about 10 meters on 30 May 2019. These images were taken from altitudes between 10 and 40 meters.” Credits: JAXA, Chiba Inst. of Tech. Via The Planetary Society

** Comets provided earth with much of its water: Comet Provides New Clues to Origins of Earth’s Oceans – NASA JPL

The mystery of why Earth has so much water, allowing our “blue marble” to support an astounding array of life, is clearer with new research into comets. Comets are like snowballs of rock, dust, ice, and other frozen chemicals that vaporize as they get closer to the Sun, producing the tails seen in images. A new study reveals that the water in many comets may share a common origin with Earth’s oceans, reinforcing the idea that comets played a key role in bringing water to our planet billions of years ago.

The Stratospheric Observatory for Infrared Astronomy, SOFIA, the world’s largest airborne observatory, observed Comet Wirtanen as it made its closest approach to Earth in December 2018. Data collected from the high-flying observatory found that this comet contains “ocean-like” water. Comparing this with information about other comets, scientists suggest in a new study that many more comets than previously thought could have delivered water to Earth. The findings were published in Astronomy and Astrophysics Letters.

** Jupiter’s magnetic field exhibits unexpected variations over time: Juno space probe identifies changes in Jupiter’s magnetic field – Physics World

An important question for the researchers to answer now is what is the cause of the shift in Jupiter’s magnetic field? On Earth, the change is thought to originate in the planet’s core, however the best explanation for secular variation on Jupiter is in its deep atmospheric (zonal) winds. These winds extend up to 3000 km into the surface of the planet, where the conductive metal fluid is situated. Although the origin of zonal winds is still uncertain, they are believed to interrupt the magnetic field distribution.

The discovery will likely have implications for the study of our Solar System. Kimee Moore, a graduate student  from the University of Cambridge and lead author of the report on the findings, says that in the future “scientists will be able to make a planet-wide map of Jupiter’s secular variation” and this latest finding may even help “scientists studying Earth’s magnetic field, which still contains many mysteries to be solved”

** Latest on the Sun’s spot count: Sunspot update May 2019: The long ramp down | Behind The Black

The Sun in May continued to show the exact same amount of activity as it had shown for March and April. This steady uptick in sunspot activity once again shows that the ramp down to full solar minimum will be long and extended.

That we are definitely ramping downward to minimum, even with the slight increase in the past three months, is shown by the fact that the Sun has shown no sunspots for the past fifteen days. In fact, all the activity shown in May comes from the first half of the month. This pattern is actually a reflection of the Sun’s 27-day rotation period. …

** A film of a solar eclipse in 1900 was found and restored: First movie of solar eclipse rediscovered | Behind The Black

The magic of a real solar eclipse filmed on 28 May, 1900 by a famous magician, Nevil Maskelyne, while on an expedition by The British Astronomical Association to North Carolina. In 1898 he travelled to India to photograph an eclipse. He succeeded but the film can was stolen on his return journey home.

It was not an easy feat to film. Maskelyne had to make a special telescopic adapter for his camera to capture the event. This is the only film by Maskelyne that we know to have survived. The original film fragment held in The Royal Astronomical Society’s archive has been painstakingly scanned and restored in 4K by conservation experts at the BFI National Archive, who have reassembled and retimed the film frame by frame.

The film is part of BFI Player’s recently released Victorian Film collection, viewers are now able to experience this first film of a solar eclipse since the event was originally captured over a century ago.

** The Stars of Cepheus as seen by NASA’s Spitzer Space Telescope:

Soar through this cosmic landscape filled with bright nebulas, as well as runaway, massive and young stars. The image comes from NASA’s Spitzer Space Telescope, which sees the universe in infrared light. For more about Spitzer, visit https://www.nasa.gov/spitzer or http://www.spitzer.caltech.edu/.

** Mars:

*** An update on Europe’s ExoMars Rover mission, which ESA plans to launch in July 2020 for a landing in March 2021: ESA Prepares for ExoMars Rover 2020 Launch at Mars and on Earth | The Planetary Society

Preparations for the ExoMars rover mission are in their final stages. ESA made two announcements today: ExoMars Trace Gas Orbiter is shifting orbit, and they officially opened a new Rover Operations Control Centre (ROCC) in Turin, Italy. ROCC will support the Rosalind Franklin rover’s deployment from the Kazachok lander and surface operations after that. Along with the announcements they posted some cool images.

*** Ten things about Mars are revealed in an interactive display from ESA.

*** Signs of even more water on Mars:

From Space.com:

Scientists think they’ve stumbled on a new cache of water ice on Mars — and not just any ice but a layered mix of ice and sand representing the last traces of long-lost polar ice caps.

That’s according to new research based on data gathered by NASA’s Mars Reconnaissance Orbiter, which has been circling the Red Planet since 2006 and has just marked its 60,000th trip around Mars. On board the spacecraft is a radar instrument that can see about 1.5 miles (2.5 kilometers) below the planet’s surface — and in that data, scientists see lots and lots of ice.

Alternating ice and sand layers on Mars
“A composite image showing alternating layers of ice and sand in an area where they are exposed on the surface of Mars. The photograph, taken with the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter, was adjusted to show water ice as light-colored layers and sand as darker layers of blue. The tiny bright white flecks are thin patches of frost.” Credit: NASA/JPL/University of Arizona. [Via AGU.org]
*** The Space Show – Fri, 05/24/2019Dr. Gilbert Levin and Dr. Patricia Ann Straat talked about the “Viking Labeled Release experiment, life detection on Mars, From Mars With Love by Dr. Straat and more”.

*** Mars reports from Bob Zimmerman:

**** Rover update: May 30, 2019 – Latest on Curiosity’s explorations (and also an update on China’s Yutu-2 rover on Moon). The image below

… one of a number taken by the rover in the past week, showing water clouds drifting over Gale Crater.

Mars clouds as seen by Curiosity
Mars clouds over Gale crater as seen by Curiosity. Via Behind the Black.

According to NASA JPL:

These are likely water-ice clouds about 19 miles (31 kilometers) above the surface. They are also “noctilucent” clouds, meaning they are so high that they are still illuminated by the Sun, even when it’s night at Mars’ surface. Scientists can watch when light leaves the clouds and use this information to infer their altitude.

But Curiosity wasn’t just looking at the clouds:

While these clouds teach us something about Martian weather, the big rover news this week was that the data obtained from the two drill holes taken in April show that the clay formation that Curiosity is presently traversing is definitely made of clay, and in fact the clay there has the highest concentration yet found by the rover.

**** Crater? Pit? Volcano? – A puzzling feature might be an impact crater but maybe not:

I would not bet much money on this conclusion. The overall terrain of the Eridania quadrangle is filled with craters, large and small. There does not seem to be any obvious evidence of past volcanic activity, and if there had been it has not expressed itself in large volcanoes.

Eridania crater
This circular feature in the Eridania region could be a meteoroid crater or a volcano caldera. Via Behind the Black.

However, other images of this mountain show many circular features that at first glance appear to be craters like the featured image. They appear slightly raised above the surrounding terrain, though not in as pronounced a manner.

They all could be small volcanoes. Or maybe they are impacts that hit a dense surface which prevented them from drilling too deep down, and instead caused the crater to be raised above the surrounding terrain.

‘Tis a puzzle. The irregular pit in this particular feature adds to the mystery. It does not look like the kind of pits one sees in calderas. Instead, its rough edge suggests wind erosion.

**** The mysterious slope streaks of Mars – Streaks on the sides of sloped surfaces are puzzling…

… and appear to possibly represent a phenomenon entirely unique to Mars. I became especially motivated to write about these mysterious ever newly appearing features when, in reviewing the May image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO), I found four different uncaptioned images of slope streaks, all titled “Slope Stream Monitoring.” From this title it was clear that the MRO team was re-imaging each location to see if any change had occurred since an earlier image was taken. A quick look in the MRO archive found identical photographs for all four slope streak locations, taken from 2008 to 2012, and in all four cases, new streaks had appeared while older streaks had faded.

Example of streaks on Martian slopes.
Example of streaks on Martian slopes. Via Behind the Black

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Brief Answers to the Big Questions
– Stephen Hawking

Space sciences roundup – May.22.2019

A sampling of recent articles, videos, and images from space-related science news items:

** Update on China’s Chang’e-4 lunar rover:

From the Planetary Society article:

The first science results from the unprecedented Chang’e-4 lunar far side mission are in. The mission’s Yutu-2 rover, deployed from the lander shortly after the Chang’e-4 landing on 3 January, has, with the help of the Queqiao relay satellite, returned data which suggests it has discovered material derived from the Moon’s mantle, according to research published today in Nature. The possibility of accessing mantle rocks exposed within an enormous impact basin was a major reason for attempting the challenging farside landing.

The Visible and Near Infrared Spectrometer (VNIS) aboard Yutu-2 made the first in situ observations—detecting scattered or reflected light from surface materials—on the lunar far side. These spectra have been interpreted by the paper’s authors to represent the presence of olivine and low-calcium pyroxene, materials that may originate from the Moon’s mantle.

Yutu-2 VNIS exploration area
VNIS payload and observation footprint – Yutu-2’s Visible and Yutu-2 rover’s Near Infrared Spectrometer (VNIS) measures an area a few centimeters across. Credits: Chunlai Li et al via Planetary Society

** SpaceIL‘s Beresheet lunar vehicle makes a mark on the Moon:

Lunar surface before/after Beresheet impact
Lunar surface before/after Beresheet impact. Planetary Society: “Left: Beresheet impact site as seen by Lunar Reconnaissance Orbiter on 22 April 2019. Right: An image processed to highlight changes near the landing site among photos taken before and after the landing, revealing a white impact halo. Other craters are visible in the right image because there is a slight change in lighting conditions among the before and after images. Scale bar is 100 meters. North is up. Both panels are 490 meters wide.”

** Greek high school student team flies experiment on the Blue Origin New Shepard: ACS Athens STEAM Experiment Blasts off into Space with Blue Origin Rocket – The National Herald

How will Greek honey and olive oil behave under microgravity conditions? What about ouzo and grape juice molasses? Will bubbles grow bigger and last longer? ACS Athens students sealed their experiment within the capsule carried by the groundbreaking Blue Origin’s New Shepard reusable rocket where it will tested at an altitude of 100 km.

ACS Athens High School students are conducting one complex STEAM (Science, Technology, Engineering, the Arts, and Mathematics) experiment, investigating how honey behaves at an altitude of 100 km. ACS Athens is one of the three non-US-based K-12 schools to have ever sent an experiment with Blue Origin

More about the team’s experiments: ACS Athens | Modeling education for the 21st Century

  • spACS 1 scientific goal is to investigate the viscosity of honey under microgravity conditions, a Physics-based experiment on fluidity. 
  • spACS 2, which won the first place in the Hellenic Physical Society’s 1st aerospace contest (November 2018), combines Physics, Chemistry, and Biology to investigate the behavior of foams and emulsions under microgravity conditions focusing on Greek traditional products (olive oil, ouzo, petimezi). 

** Update on OSIRIS-REx at the Bennu asteroid: Here’s a Roundup of Recent OSIRIS-REx Postcards from Bennu | The Planetary Society

NASA’s OSIRIS-REx spacecraft is continuing to chug along at asteroid Bennu. It’s currently sweeping arcs between the asteroid’s north and south poles, gathering scientific data that will also be used to select 12 possible sites for sample collection. The OSIRIS-REx team has also been releasing stunning new images from the mission’s prior phase.

More about the OSIRIS-REx spacecraft and mission:

** Examining the rough plains of the Marineris Valles: The floor of Marineris Valles | Behind The Black

The photograph, uncaptioned, is titled “Terminus of Pitted Materials Emanating from Oudemans Crater.” Oudemans Crater is about 55 miles across and is located near the head of Marineris Valles to the east of the giant volcanic region dubbed the Tharsis Bulge. The meteorite that caused this crater is estimated to have been a little less than 3 miles in diameter. It is believed by some scientists that the impact heated up subsurface carbon dioxide permafrost which then explosively flooded down the Valles Marineris into the Northern Plains of Mars, pushing a lot of pulverized debris in front of it.

A section of the floor of Marineris Valles.
A section of the floor of Marineris Valles. Credits: MRO/HiRISE via Bob Zimmerman

** NASA’s Curiosity Finds Climate Clues on a Martian Mountain – A brief update on Curiosity’s travels:

After spending the better part of a year exploring Mars’ Vera Rubin Ridge, NASA’s Curiosity Mars rover has moved to a new part of Mount Sharp. Project Scientist Ashwin Vasavada gives a tour of the rover’s new home in the “clay unit,” as well as other areas scientists are excited to visit. Find out what they could tell us about watery ancient Mars versus the dry Red Planet we see today.

** Charon, Pluto’s Companion: What We Learned from New Horizons – Dr. Ross Beyer (SETI Institute) gave this recent public lecture in the Silicon Valley Astronomy Series:

Pluto’s large moon Charon turned out to be far more interesting than astronomers expected. Pluto was the star of the New Horizons show, but the features on Charon’s surface tell a fascinating tale of how icy worlds could form far from the gravitational influences of the giant planets. There is evidence of a world-wide sub-surface ocean early on, and of global expansion as that ocean froze solid. Dr. Beyer is your expert (and humorous) guide through this story of formation and change in the frozen reaches of the outer Solar System.

** Dr. Linda Spilker spoke about the latest findings from the Cassini Mission data, “new information on Saturn’s ring system, Titan, Enceladus, liquid methane oceans, life, NASA missions and more” – The Space Show – Friday, 05/17/2019

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Chasing New Horizons:
Inside the Epic First Mission to Pluto

Space sciences roundup – April.24.2019

A sampling of recent articles, videos, and images from space-related science news items:

** The InSight Mars Lander detects its first Marsquake using the seismometer set on the ground next to the spacecraft:

From NASA:

NASA’s Mars InSight lander has measured and recorded for the first time ever a likely “marsquake.”

The faint seismic signal, detected by the lander’s Seismic Experiment for Interior Structure (SEIS) instrument, was recorded on April 6, the lander’s 128th Martian day, or sol. This is the first recorded trembling that appears to have come from inside the planet, as opposed to being caused by forces above the surface, such as wind. Scientists still are examining the data to determine the exact cause of the signal.

This image, taken March 19, 2019 by a camera on NASA’s Mars InSight lander, shows the rover’s domed Wind and Thermal Shield, which covers its seismometer, the Seismic Experiment for Interior Structure, and the Martian surface in the background. Credits: NASA/JPL-Caltech

The seismometer signals can be converted to audio:

This video and audio illustrates a seismic event detected by NASA’s Mars InSight rover on April 6, 2019, the 128th Martian day, or sol, of the mission. Three distinct kinds of sounds can be heard, all of them detected as ground vibrations by the spacecraft’s seismometer, called the Seismic Experiment for Interior Structure (SEIS): noise from Martian wind, the seismic event itself, and the spacecraft’s robotic arm as it moves to take pictures. Credits: NASA/JPL-Caltech/CNES/IPGP/Imperial College London.

The new seismic event was too small to provide solid data on the Martian interior, which is one of InSight’s main objectives. The Martian surface is extremely quiet, allowing SEIS, InSight’s specially designed seismometer, to pick up faint rumbles. In contrast, Earth’s surface is quivering constantly from seismic noise created by oceans and weather. An event of this size in Southern California would be lost among dozens of tiny crackles that occur every day.

“The Martian Sol 128 event is exciting because its size and longer duration fit the profile of moonquakes detected on the lunar surface during the Apollo missions,” said Lori Glaze, Planetary Science Division director at NASA Headquarters.

Note that the signals’ frequencies “have been sped up by a factor of 60” since otherwise the vibrations would not be audible to the human ear.

** More quakes in the Cosmos are being detected more quickly with newly upgraded gravity wave observatories in the US and Italy. The sensitivities of the detectors have been increased to a level such that signals picked up at the LIGO (Laser Interferometer Gravitational-Wave Observatory) installations in Louisiana, and Washington plus the European Virgo detector in Italy will result in roughly one gravity wave detection per week. A new public alert system will let everyone know when a detection occurs:

From PSU:

Two new probable gravitational waves — ripples in the fabric of spacetime caused by cataclysmic cosmic events and first predicted by Albert Einstein over 100 years ago — have been detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo observatory in Italy in the first weeks after the detectors were updated. The source of both waves is believed to be the merging of a pair of black holes.

LIGO announced the discovery of the first new gravitational wave in its first-ever open public alert on April 8, and quickly followed up with a second announcement on April 12. LIGO detected the first-ever gravitational wave in September 2015, and announced the discovery in February 2016. Ten more gravitational waves were detected over the following three years, but with updates to LIGO and Virgo, scientists expect to see as many as one per week, which so far has proven true.

Updates to LIGO and Virgo have combined to increase its sensitivity by about 40 percent over its last run. Additionally, with this third observing run, LIGO and Virgo transitioned to a system whereby they alert the astronomy community almost immediately of a potential gravitational wave detection. This allows electromagnetic telescopes (X-ray, UV, optical, radio) to search for and hopefully find an electromagnetic signal from the same source, which can be key to understanding the dynamics of the event.

“The region of sky believed to contain the source of the gravitational wave detected on April 8, 2019. The area spans 387 square degrees, equivalent to nearly 2000 full-Moons, roughly meandering through the constellations Cassiopeia, Lacerta, Andromeda, and Cepheus in the northern hemisphere. IMAGE: LIGO/Caltech/MIT”

… The source of both gravitational waves is suspected to be compact binary mergers — the collision of two massive and incredibly dense cosmic objects into one another. Compact binary mergers can occur between two neutron stars, two black holes, or a neutron star and a black hole. Each of these different types of mergers create gravitational waves with strikingly different signals, so the LIGO team can identify the type of event that created the gravitational waves.

** Huge gallery of Rosetta mission images of comet 67P/Churyumov-Gerasimenko is now available on line at the OSIRIS Image Archive:

The ESA release says the image shown below

… was taken on 6 October 2014 from a distance of 18.6 km to the comet. This is just one of almost 70 000 images taken with Rosetta’s high-resolution imaging system OSIRIS that are now available via a new online and mobile-friendly ‘comet viewer’ created in a joint project with the Department of Information and Communication at Flensburg University of Applied Sciences, and the Max Planck Institute for Solar System Research, who lead the OSIRIS team.

A feature of  Comet 67P/Churyumov-Gerasimenko: “Seen from afar, the comet is usually likened to a duck in shape, but in this enchanting close-up view its profile resembles that of a cat’s face seen side-on. The two ‘ears’ of the cat make up the twin peaks either side of the ‘C. Alexander Gate’ – named for US Rosetta Project Scientist Claudia Alexander who passed away in July 2015. These impressive cliffs lie at the border between the Serqet and Anuket regions on the comet’s head.”

The image viewer hosts the full archive, but also has subsections organising image sets into themes: for example, images showing towering cliffs and bizarre cracks on the comet surface, or those focusing on spectacular dust fountains as the comet launched gas and dust jets into space as its surface ices were warmed as it came closer to the Sun on its orbit.

The collection of OSIRIS images captured the farewell of lander Philae as it dropped towards the surface of the comet, and later, towards the end of the mission, the feverish search for the hidden robot.

Within the new comet viewer, each of the nearly 70 000 images is supplemented with the date on which it was taken, the distance to the comet, and a short accompanying text briefly describing what is seen in the image. The images can be downloaded in full resolution and can also be directly shared to Twitter and Facebook.

** The Southern Crab Nebula shines in a new Hubble image marking 29 years in orbit for the space telescope: Hubble Celebrates its 29th Birthday with Unrivaled View of the Southern Crab Nebula | ESA/Hubble

This incredible image of the hourglass-shaped Southern Crab Nebula was taken to mark the NASA/ESA Hubble Space Telescope’s 29th anniversary in space. The nebula, created by a binary star system, is one of the many objects that Hubble has demystified throughout its productive life. This new image adds to our understanding of the nebula and demonstrates the telescope’s continued capabilities.

The Southern Crab Nebula — Hubble’s 29th anniversary image.

On 24 April 1990, the NASA/ESA Hubble Space Telescope was launched on the space shuttle Discovery. It has since revolutionised how astronomers and the general public see the Universe. The images it provides are spectacular from both a scientific and a purely aesthetic point of view.

Each year the telescope dedicates a small portion of its precious observing time to take a special anniversary image, focused on capturing particularly beautiful and meaningful objects. This year’s image is the Southern Crab Nebula, and it is no exception [1].

This peculiar nebula, which exhibits nested hourglass-shaped structures, has been created by the interaction between a pair of stars at its centre. The unequal pair consists of a red giant and a white dwarf. The red giant is shedding its outer layers in the last phase of its life before it too lives out its final years as a white dwarf. Some of the red giant’s ejected material is attracted by the gravity of its companion.

More highlights from Hubble’s 29 years in orbit:

** Latest Mars updates from Bob Zimmerman:

Comparison of an area near Olympus Mars before (left) and after (right) the global dust storm of 2018. Credits: Bob Zimmerman & HiRISE camera on NASA Mars Reconnaissance Orbiter (MRO)
White streaks atop avalanche debris on this Mars slope appear to be water frost. Credits: Bob Zimmerman + HiRISE camera on NASA Mars Reconnaissance Orbiter (MRO)

Check out a new MRO avalanche image released today by NASA: Landslides in Mars’ Cerberus Fossae | NASA.

The Mast Camera, or Mastcam, on NASA’s Curiosity Mars rover captured this image after “it drilled a rock nicknamed “Aberlady,” on Saturday, April 6, 2019 (the 2,370th Martian day, or sol, of the mission). The rock and others nearby appear to have moved when the drill was retracted. This was the first time Curiosity has drilled in the long-awaited “clay-bearing unit.” See also a GIF animation showing before and after the drilling. Credits: NASA JPL
  • How fast do things change on Mars? – A comparison of Mars Reconnaissance Orbiter images of a dune-like feature on Mars taken 12 years apart show some differences. “Overall, however, not much is different. Though dunes definitely change on Mars, they do so much more slowly than on Earth. And in some cases what look like dunes are not really dunes at all, but a form of cemented sandstone, exhibiting even fewer changes over long time spans.”

** Some space sciences webcasts:

>> Weekly Space Hangout: Apr 17, 2019 – Dr. Dorothy Oehler Talks “Is there Methane on Mars?”

>> SETI Institute: Tiny Neptune Moon Spotted by Hubble May Have Broken from Larger Moon

>> SETI Institute: Mars Exploration Rovers: Spirit and Opportunity with Nathalie Cabrol

>> SETI Institute: Turkish Meteorite Traced to Impact Crater on Asteroid Vesta

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Archaeology from Space: How the Future Shapes Our Past