Category Archives: Astronomy

Astronomy, Solar Science, Space Science

Space sciences roundup – Jan.4.2020

A sampling of recent articles, videos, and images from space-related science news items (find previous roundups here):

** Reviews of major space science news in 2019 and the past decade:

Astronomy

** Is Betelgeuse about to go supernova?  Recent dimming of the red super giant star got people discussing the possibility, but it’s unlikely to happen anytime soon (on a human timescale). Here are a couple of discussions of Betelgeuse by Scott Manley and Fraser Cain:

Exoplanets

** NASA’s ASTERIA goes silent after successfully demonstrating a low-cost smallsat can do exoplanet searches. Tiny Satellite for Studying Distant Planets Goes Quiet – NASA JPL

ASTERIA observed a handful of nearby stars and successfully demonstrated that it could achieve precision measurements of the stars’ brightness. With that data, scientists look for dips in a star’s light that would indicate an orbiting planet passing between the satellite and the star. (This planet-hunting technique is called the transit method.) Mission data is still being analyzed to confirm whether ASTERIA spotted any distant worlds.

Since completing its primary mission objectives in early February 2018, ASTERIA has continued operating through three mission extensions. During that time, it has been used as an in-space platform to test various capabilities to make CubeSats more autonomous, some of which are based on artificial intelligence programs. ASTERIA also made opportunistic observations of the Earth, a comet, other spacecraft in geo-synchronous orbit and stars that might host transiting exoplanets.

“Left to right: Electrical Test Engineer Esha Murty and Integration and Test Lead Cody Colley prepare the ASTERIA spacecraft for mass-properties measurements in April 2017 prior to spacecraft delivery ahead of launch. ASTERIA was deployed from the International Space Station in November 2017. Credit: NASA/JPL-Caltech” > Larger view

** Planetary Imaging Concept Testbed Using a Recoverable Experiment – Coronagraph (PICTURE-C)  tests techniques for direct imaging of exoplanets: A real-life deluminator for spotting exoplanets by reflected starlight – The Conversation

PICTURE-C’s coronagraph creates artificial eclipses to dim or eliminate starlight without dimming the planets that the stars illuminate. It is designed to capture faint asteroid belt like objects very close to the central star.

While a coronagraph is necessary for direct imaging of exoplanets, our 6,000 pound device also includes deformable mirrors to correct the shape of the the telescope mirrors that get distorted due to changes in gravity, temperature fluctuations and other manufacturing imperfections.

Finally, the entire device has to be held steady in space for relatively long periods of time. A specially NASA-designed gondola called Wallops Arc Second Pointer (WASP) carried PICTURE-C and got us part way. An internal image stabilization system designed by my colleagues provided the “steady hand” necessary.

Sun

** Sunspots return. After an unusually long period of about six months with few or zero spots, several appeared on the face of the Sun in December. They also displayed the change in magnetic polarization that indicates they belong to the next phase of the solar cycle. The Next Solar Cycle is Coming – SpaceWeather.com

The pace of new-cycle sunspots is definitely intensifying. 2020 is only three days old, and already there is a Solar Cycle 25 ‘spot on the sun: AR2755. The sunspot is inset in this magnetic map from NASA’s Solar Dynamics Observatory:

We know that AR755 belongs to the next solar cycle because of its magnetic polarity. It’s reversed. According to Hale’s Law, sunspot polarities flip-flop from one solar cycle to the next. During old Solar Cycle 24, we grew accustomed to sunspots in the sun’s southern hemisphere having a -/+ pattern. AR2755 is the reverse: +/-, marking it as a member of new Solar Cycle 25.

This is the 3rd consecutive month that Solar Cycle 25 sunspots have appeared: Nov. 2019, Dec. 2019, and now Jan. 2020. The quickening pace of new cycle sunspots does not mean that Solar Minimum is finished. On the contrary, low sunspot counts will likely continue for many months and maybe even years. However, it is a clear sign that Solar Cycle 25 is coming to life. The doldrums won’t last forever.

Bob Zimmerman wrote back in December about the current minimum in the solar cycle, which, even with the rise of a few new spots, is unusually long: Sunspot update Nov 2019: The longest flatline in centuries | Behind The Black

The Sun is now in what appears to be the longest stretch ever recorded, since the 11-year solar sunspot cycle reactivated in the 1700s after the last grand minimum, of sunspot inactivity. This record-setting dearth of practically no sunspots has now stretched to six months in a row.

Moon

** China’s Chang’e 4 lander and rover mission continues 1 year after landing on the far side of the Moon on January 3rd, 2019.

Asteroids and Comets

** Planetary Society announces winners of latest Shoemaker NEO Grant awards: Announcing the 2019 Shoemaker NEO Grant Winners | The Planetary Society

[The] grants support very advanced amateur astronomers around the world in their efforts to find, track, and characterize near Earth asteroids. 

The world’s professional sky surveys alone cannot handle the burden of defending the Earth from potentially dangerous asteroids. Our Shoemaker grant winners contribute in particular to two areas of planetary defense: 

    • Characterization: Some winners focus on asteroid characterization to determine asteroid properties. They typically carry out photometry (brightness) studies to determine properties like spin rate and whether what looks like one asteroid is actually two asteroids—a binary pair. This type of information will be crucial when an asteroid deflection is required, and in the meantime, for understanding the near-Earth asteroid population in general. 
    • Tracking: Other winners focus on astrometric (sky position) tracking observations that are necessary for calculating orbits, which tells us whether an asteroid will hit Earth. Without these follow-up observations of newly discovered asteroids, the asteroids can even be lost.

** SETI Institute‘s Senior Astronomer Seth Shostak discusses Comet 2I/B Borisov:

** OSIRIS-REx mission selects spot on asteroid Bennu to collect the sample that will be returned to Earth: X Marks the Spot: NASA Selects Site for Asteroid Sample Collection – OSIRIS-REx Mission

“The sample site Nightingale, OSIRIS-REx’s primary sample collection site on asteroid Bennu. The image is overlaid with a graphic of the OSIRIS-REx spacecraft to illustrate the scale of the site. Credit: NASA/Goddard/University of Arizona”

Mars

** First Drive Test of NASA’s Mars 2020 Rover – NASA JPL

On Dec. 17, 2019, engineers took NASA’s next Mars rover for its first spin. The test took place in the Spacecraft Assembly Facility clean room at NASA’s Jet Propulsion Laboratory in Pasadena, California. This was the first drive test for the new rover, which will move to Cape Canaveral, Florida, in the beginning of next year to prepare for its launch to Mars in the summer. Engineers are checking that all the systems are working together properly, the rover can operate under its own weight, and the rover can demonstrate many of its autonomous navigation functions. The launch window for Mars 2020 opens on July 17, 2020. The rover will land at Mars’ Jezero Crater on Feb. 18, 2021.

More about the Mars 2020 rover: Media Get a Close-Up of NASA’s Mars 2020 Rover – NASA’s Mars Exploration Program

Scheduled to launch in July or August 2020, the Mars 2020 rover will land in Jezero Crater on Feb. 18, 2021. There it will search for signs of past microbial life, characterize Mars’ climate and geology, collect samples for future return to Earth and pave the way for human exploration of the Red Planet.

Both to ensure that as few Earthly microbes as possible hitch a ride to Mars and to keep out particles that could interfere with the rover’s operations, High Bay 1 comes with strict cleanliness standards: Anyone entering the clean room, whether a technician or a journalist, must wear a “bunny suit,” booties, a hair cover, a face mask and latex gloves. Because notepads and writing implements could shed dust and other particles, specially-approved paper and pens were provided to visiting media members on request.

In the coming weeks, engineers and technicians will pack the 2020 rover into a specially-designed container. After it arrives at the Cape, Mars 2020 will undergo final processing and testing before launch.

Mars 2020 Media Day

** Updates on Curiosity’s roving from Leonard David:

Curiosity Right B Navigation Camera photo taken on Sol 2634, January 3, 2020. Credit: NASA/JPL-Caltech

** More analysis of images of the marvelous Martian surface – Bob Zimmerman

Darkened craters on the Elysium Planitia plain. Credits: NASA/Arizona State Univ. via Behind the Black. Full image.

** Are We About to Find Life on Mars? – SETI Institute

Over the past six months, numerous articles have reported weird anomalies in the atmosphere of Mars, from an outburst of methane in June 2019 to patterns in oxygen concentrations that cannot be explained by any known atmospheric or surface processes on the Red Planet. Perhaps more intriguing is the Viking Lander (Viking LR) experiment. In 1976, each of the two Viking landers performed experiments on Martian soil samples. The samples tested positive for metabolism, and researchers recently claimed that like on Earth, this is a sign for the presence of a Martian life. Finally, an Ohio scientist claims to have found photographic proof of “insect and reptile-like” life on Mars. This controversial result has been discussed at length in the media, even though most scientists rejected it.

What does this mean? Are we on the verge of announcing the most profound story since humans first wondered about the existence of life elsewhere? Or are these coincidences that can be explained by geological processes, failed experiments or pareidolia?

We invited two SETI Institute scientists who are experts on Mars to discuss these exciting and out of this world results. Biologist Kathryn Bywaters who has studied life in some of the most extreme environments on Earth and planetary scientist Pascal Lee who focuses on water on Mars and human exploration of the Red Planet. Both scientists will tell us if indeed we are about to discover life on Mars and the consequences of this significant discovery.

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Astronomy

Videos: Night sky highlights for January 2020

A preview of the January night sky from NASA JPL: What’s Up: Skywatching Tips from NASA – NASA Solar System Exploration

** What’s in the Night Sky January 2020 – Ayn Wallace

[ Update: Tonight’s Sky: January 2020 – Space Telescope Science Institute

In January, the northern hemisphere features beautiful views of Capella, a pair of giant yellow stars; Aldebaran, a red giant star; and two star clusters—the Hyades and the Pleiades. Keep watching for the awe-inspiring space-based views of the Crab Nebula, the remains of a star that exploded as a supernova.

]

** January 2020: Mid-winter Wonders – Sky & Telescope

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Imagined Life: A Speculative Scientific Journey among the Exoplanets
in Search of Intelligent Aliens, Ice Creatures, and Supergravity Animals

Astronomy

ESO: VLT spots gas halos that fed black holes in earliest galaxies

A new ESO (European Southern Observatory) report:

ESO Observations Reveal Black Holes’ Breakfast at the Cosmic Dawn

This image shows one of the gas halos newly observed with the MUSE instrument on ESO’s Very Large Telescope superimposed to an older image of a galaxy merger obtained with ALMA. The large-scale halo of hydrogen gas is shown in blue, while the ALMA data is shown in orange.  The halo is bound to the galaxy, which contains a quasar at its centre. The faint, glowing hydrogen gas in the halo provides the perfect food source for the supermassive black hole at the centre of the quasar.  The objects in this image are located at redshift 6.2, meaning they are being seen as they were 12.8 billion years ago. While quasars are bright, the gas reservoirs around them are much harder to observe. But MUSE could detect the faint glow of the hydrogen gas in the halos, allowing astronomers to finally reveal the food stashes that power supermassive black holes in the early Universe.

Astronomers using ESO’s Very Large Telescope have observed reservoirs of cool gas around some of the earliest galaxies in the Universe. These gas halos are the perfect food for supermassive black holes at the centre of these galaxies, which are now seen as they were over 12.5 billion years ago. This food storage might explain how these cosmic monsters grew so fast during a period in the Universe’s history known as the Cosmic Dawn.

“We are now able to demonstrate, for the first time, that primordial galaxies do have enough food in their environments to sustain both the growth of supermassive black holes and vigorous star formation,”

says Emanuele Paolo Farina, of the Max Planck Institute for Astronomy in Heidelberg, Germany, who led the research published today in The Astrophysical Journal.

“This adds a fundamental piece to the puzzle that astronomers are building to picture how cosmic structures formed more than 12 billion years ago.”

Astronomers have wondered how supermassive black holes were able to grow so large so early on in the history of the Universe.

“The presence of these early monsters, with masses several billion times the mass of our Sun, is a big mystery,”

says Farina, who is also affiliated with the Max Planck Institute for Astrophysics in Garching bei München.

It means that the first black holes, which might have formed from the collapse of the first stars, must have grown very fast. But, until now, astronomers had not spotted ‘black hole food’ — gas and dust — in large enough quantities to explain this rapid growth.

To complicate matters further, previous observations with ALMA, the Atacama Large Millimeter/submillimeter Array, revealed a lot of dust and gas in these early galaxies that fuelled rapid star formation. These ALMA observations suggested that there could be little left over to feed a black hole.

This illustration depicts a gas halo surrounding a quasar in the early Universe. The quasar, in orange, has two powerful jets and a supermassive black hole at its centre, which is surrounded by a dusty disc. The gas halo of glowing hydrogen gas is represented in blue. A team of astronomers surveyed 31 distant quasars, seeing them as they were more than 12.5 billion years ago, at a time when the Universe was still an infant, only about 870 million years old. They found that 12 quasars were surrounded by enormous gas reservoirs: halos of cool, dense hydrogen gas extending 100 000 light years from the central black holes and with billions of times the mass of the Sun. These gas stashes provide the perfect food source to sustain the growth of supermassive black holes in the early Universe.

To solve this mystery, Farina and his colleagues used the MUSE instrument on ESO’s Very Large Telescope (VLT) in the Chilean Atacama Desert to study quasars — extremely bright objects powered by supermassive black holes which lie at the centre of massive galaxies. The study surveyed 31 quasars that are seen as they were more than 12.5 billion years ago, at a time when the Universe was still an infant, only about 870 million years old. This is one of the largest samples of quasars from this early on in the history of the Universe to be surveyed.

The astronomers found that 12 quasars were surrounded by enormous gas reservoirs: halos of cool, dense hydrogen gas extending 100 000 light years from the central black holes and with billions of times the mass of the Sun. The team, from Germany, the US, Italy and Chile, also found that these gas halos were tightly bound to the galaxies, providing the perfect food source to sustain both the growth of supermassive black holes and vigorous star formation.

The research was possible thanks to the superb sensitivity of MUSE, the Multi Unit Spectroscopic Explorer, on ESO’s VLT, which Farina says was “a game changer” in the study of quasars.

“In a matter of a few hours per target, we were able to delve into the surroundings of the most massive and voracious black holes present in the young Universe,”

he adds. While quasars are bright, the gas reservoirs around them are much harder to observe. But MUSE could detect the faint glow of the hydrogen gas in the halos, allowing astronomers to finally reveal the food stashes that power supermassive black holes in the early Universe.

In the future, ESO’s Extremely Large Telescope (ELT) will help scientists reveal even more details about galaxies and supermassive black holes in the first couple of billion years after the Big Bang.

“With the power of the ELT, we will be able to delve even deeper into the early Universe to find many more such gas nebulae,”

Farina concludes.

Links

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Astronomy, Education, Exoplanets

Video: An overview of finding and studying exoplanets

Dr. Courtney Dressing of the University of California at Berkeley gives a public lecture on exoplanets:

The NASA Kepler mission revealed that our Galaxy is teeming with planetary systems and that Earth-sized planets are common. However, most of the planets detected by Kepler orbit stars too faint to permit detailed study. The NASA Transiting Exoplanet Survey Satellite (TESS,) launched in 2018, is now finding hundreds of small planets orbiting stars that are much closer and brighter. Dr. Dressing discusses how we find exoplanets, describes the TESS mission, and explains how it (and future projects) will help our understanding of what planets are out there and how they form.

The lecture is one in the Silicon Valley Astronomy Lectures  series organized and moderated by Foothill’s astronomy instructor Andrew Fraknoi and jointly sponsored by the Foothill College Astronomy Department, NASA’s Ames Research Center, the SETI Institute, and the Astronomical Society of the Pacific.

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Astronomy

ESO: VLT detects ancient burst of star formation in Milky Way core

A new report from the European Southern Observatory (ESO):

ESO Telescope Images Stunning Central Region of Milky Way,
Finds Ancient Star Burst

Taken with the HAWK-I instrument on ESO’s Very Large Telescope in the Chilean Atacama Desert, this stunning image shows the Milky Way’s central region with an angular resolution of 0.2 arcseconds. This means the level of detail picked up by HAWK-I is roughly equivalent to seeing a football (soccer ball) in Zurich from Munich, where ESO’s headquarters are located. The image combines observations in three different wavelength bands. The team used the broadband filters J (centred at 1250 nanometres, in blue), H (centred at 1635 nanometres, in green), and Ks (centred at 2150 nanometres, in red), to cover the near infrared region of the electromagnetic spectrum. By observing in this range of wavelengths, HAWK-I can peer through the dust, allowing it to see certain stars in the central region of our galaxy that would otherwise be hidden.

ESO’s Very Large Telescope (VLT) has observed the central part of the Milky Way with spectacular resolution and uncovered new details about the history of star birth in our galaxy. Thanks to the new observations, astronomers have found evidence for a dramatic event in the life of the Milky Way: a burst of star formation so intense that it resulted in over a hundred thousand supernova explosions.

“Our unprecedented survey of a large part of the Galactic centre has given us detailed insights into the formation process of stars in this region of the Milky Way,”

says Rainer Schödel from the Institute of Astrophysics of Andalusia in Granada, Spain, who led the observations.

“Contrary to what had been accepted up to now, we found that the formation of stars has not been continuous,”

adds Francisco Nogueras-Lara, who led two new studies of the Milky Way central region while at the same institute in Granada.

Caption: ESO’s Very Large Telescope (VLT) has observed the central part of the Milky Way with spectacular resolution and uncovered new details about the history of star birth in our galaxy. Watch this video summary to find out more about the stunning image captured with the HAWK-I instrument on the VLT and the discoveries made about star formation in the central region of our galaxy.

In the study, published today in Nature Astronomy, the team found that about 80% of the stars in the Milky Way central region formed in the earliest years of our galaxy, between eight and 13.5 billion years ago. This initial period of star formation was followed by about six billion years during which very few stars were born. This was brought to an end by an intense burst of star formation around one billion years ago when, over a period of less than 100 million years, stars with a combined mass possibly as high as a few tens of million Suns formed in this central region.

“The conditions in the studied region during this burst of activity must have resembled those in ‘starburst’ galaxies, which form stars at rates of more than 100 solar masses per year,”

says Nogueras-Lara, who is now based at the Max Planck Institute for Astronomy in Heidelberg, Germany. At present, the whole Milky Way is forming stars at a rate of about one or two solar masses per year.

“This burst of activity, which must have resulted in the explosion of more than a hundred thousand supernovae, was probably one of the most energetic events in the whole history of the Milky Way,”

he adds. During a starburst, many massive stars are created; since they have shorter lifespans than lower-mass stars, they reach the end of their lives much faster, dying in violent supernova explosions.

Caption: This video compares a visible light wide-field view (part of the Digitized Sky Survey 2) of the Milky Way’s central regions with a new near-infrared image taken with the HAWK-I instrument on ESO’s Very Large Telescope. The video starts by showing a visible light image of the Milky Way central regions, filled with vast numbers of stars. A moving slider then reveals that far more stars, hidden behind clouds of dust, are revealed when this region is observed in the near-infrared.

This research was possible thanks to observations of the Galactic central region done with ESO’s HAWK-I instrument on the VLT in the Chilean Atacama Desert. This infrared-sensitive camera peered through the dust to give us a remarkably detailed image of the Milky Way’s central region, published in October in Astronomy & Astrophysics by Nogueras-Lara and a team of astronomers from Spain, the US, Japan and Germany. The stunning image shows the galaxy’s densest region of stars, gas and dust, which also hosts a supermassive black hole, with an angular resolution of 0.2 arcseconds. This means the level of detail picked up by HAWK-I is roughly equivalent to seeing a football (soccer ball) in Zurich from Munich, where ESO’s headquarters are located.

Caption: This video compares a view of the Galactic centre captured with the VISTA infrared survey telescope, as part of the Variables in the Via Lactea (VVV) ESO public survey, and a new, sharper view of the same region obtained with the HAWK-I instrument on ESO’s Very Large Telescope.

This image is the first release of the GALACTICNUCLEUS survey. This programme relied on the large field of view and high angular resolution of HAWK-I on ESO’s VLT to produce a beautifully sharp image of the central region of our galaxy. The survey studied over three million stars, covering an area corresponding to more than 60 000 square light-years at the distance of the Galactic centre (one light-year is about 9.5 trillion kilometres).

Caption: This video pans across the central regions of the Milky Way, newly observed with the HAWK-I instrument on ESO’s Very Large Telescope in the Chilean Atacama Desert. This stunning view shows the Milky Way’s central region with an angular resolution of 0.2 arcseconds.

Links

This beautiful image of the Milky Way’s central region, taken with the HAWK-I instrument on ESO’s Very Large Telescope, shows interesting features of this part of our galaxy. This image highlights the Nuclear Star Cluster (NSC) right in the centre and the Arches Cluster, the densest cluster of stars in the Milky Way. Other features include the Quintuplet cluster, which contains five prominent stars, and a region of ionised hydrogen gas (HII).

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Einstein’s Monsters:
The Life and Times of Black Holes