Category Archives: Astronomy

Astronomy, Space Science

Space sciences roundup – April.10.2019

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

** Radio telescope array images a black hole for the first time. This is the big news not just of the week but for 2019: First Image of a Black Hole | ESO –

The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole. In coordinated press conferences across the globe, EHT researchers revealed that they succeeded, unveiling the first direct visual evidence of the supermassive black hole in the centre of Messier 87 and its shadow.

The shadow of a black hole seen here is the closest we can come to an image of the black hole itself, a completely dark object from which light cannot escape. The black hole’s boundary — the event horizon from which the EHT takes its name — is around 2.5 times smaller than the shadow it casts and measures just under 40 billion km across. While this may sound large, this ring is only about 40 microarcseconds across — equivalent to measuring the length of a credit card on the surface of the Moon.

Although the telescopes making up the EHT are not physically connected, they are able to synchronize their recorded data with atomic clocks — hydrogen masers — which precisely time their observations. These observations were collected at a wavelength of 1.3 mm during a 2017 global campaign. Each telescope of the EHT produced enormous amounts of data – roughly 350 terabytes per day – which was stored on high-performance helium-filled hard drives. These data were flown to highly specialised supercomputers — known as correlators — at the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory to be combined. They were then painstakingly converted into an image using novel computational tools developed by the collaboration.

Chandra X-ray Observatory close-up of the core of the M87 galaxy. Credits: NASA/CXC/Villanova University/J. Neilsen

More at:

** SpaceIL Beresheet spacecraft will land on the Moon tomorrow April 11th, hopefully softly. The Israeli privately developed vehicle made orbit corrections this past week that brought the vehicle into the final close lunar orbit in preparation for the landing firing: Find updates at Israel To The Moon (@TeamSpaceIL) | Twitter.

Resources for the mission:

There will be a webcast of the landing. The estimated landing times:

  • 22:00 – 23:00 Israel
  • 19:00 – 20:00 UTC
  • 15:00 – 16:00 EDT
  • 12:00 – 13:00 PDT

Some info on the landing site: Beresheet lunar landing site revealed 3 April 2019 – Weizmann Institute of Science.

** Launch of the Indian Chandrayaan 2 lunar lander/rover mission will be delayed somewhat due to some minor damage during a test: Chandrayaan 2: Vikram hurt during practice, puts Chandrayaan-2 on bench – Times of India

Vikram, the Lander on India’s ambitious mission that envisages to land a probe on Moon, has suffered minor injuries in two of its legs during a test late February, putting Chandrayaan-2 on the bench at least until May. But the need to find the most suitable launch window could see the mission take off only in the second half of the year.

A source in the know, said: “The rover and orbiter are in good health and tests met all the parameters. However, after the ‘Lander Drop Test’, we found that Vikram (the lander) needed to be strengthened in its legs. Prima facie, it appears that not all parameters were set correctly before the test, it could also be that the additional mass—a result of the new configuration—caused the problem.”

** Curiosity captures Demos and Phobos eclipses of the Sun: Curiosity Captured Two Solar Eclipses on Mars | NASA

When NASA’s Curiosity Mars rover landed in 2012, it brought along eclipse glasses. The solar filters on its Mast Camera (Mastcam) allow it to stare directly at the Sun. Over the past few weeks, Curiosity has been putting them to good use by sending back some spectacular imagery of solar eclipses caused by Phobos and Deimos, Mars’ two moons.

Phobos, which is as wide as 16 miles (26 kilometers) across, was imaged on March 26, 2019 (the 2,359th sol, or Martian day, of Curiosity’s mission); Deimos, which is as wide as 10 miles (16 kilometers) across, was photographed on March 17, 2019 (Sol 2350). Phobos doesn’t completely cover the Sun, so it would be considered an annular eclipse. Because Deimos is so small compared to the disk of the Sun, scientists would say it’s transiting the Sun.

** More Martian image commentaries from Bob Zimmerman:

  • A dance of dust devils – “Many of my image posts about Mars have emphasized how slowly things change there. This post will highlight the exact opposite. When it comes to dust devils, it appears they can leave their trace frequently and often, and for some reason they seem to also favor specific locations.“
  • Monitoring the ice scarps on Mars for changes – “Monitoring these scraps will be crucial for future exploration. The ice here is very readily available, as it is exposed and should be relatively easy to access. Moreover, tracking might tell us whether it will be easier to get at this ice from the top of the cliff by drilling down, or approach it from the bottom. Some of the ice bands in these scarps was very close to the surface at the top of the cliff.“
  • A decade of changes at the Martian south pole – “The mystery here is that these images were both taken at almost the same moment in the late southern summer, though about five Martian years apart. Why should the white areas have shrunk? We would expect a reduction from winter to summer, but these were both taken in summer. While it would make sense to see changes, with some areas growing and others shrinking, we should expect to see about the same amount of white area.“
Dust devil trails in southern highlands of Mars. Credits: Mars Reconnaissance Orbiter HiRISE camera.

** Martian soil studies may bring medical spinoff benefits: Martian soil detox could lead to new medicines – ESA

“During their experiments they noticed that when bacteria grew in partial gravity, they became stressed as they accumulated waste around them that they couldn’t get rid of. This holds great potential because when microbes belonging to the Streptomyces family become stressed, they usually start making antibiotics,” adds Prof. Claessen.

“Seventy percent of all the antibiotics humans use are derived from Streptomyces bacteria and we know they have the potential to produce even more. Using the RPM to stress them in new ways may help us to find ones we’ve never seen before.”

** Hayabusa2 successfully fired a projectile into Ryuga to investigate the asteorid’s surface structure:

Debris from the impact of the projectile shot from Hayabusa2 can be seen in this cropped section of an image taken by the DCAM3 free-flying imager. Hayabusa2 went to the far side of Ryuga to wait for the debris to settle back to the surface.


Here is the full image:

** Parker Solar Probe makes another close pass of the Sun –

From the Parker Solar Probe mission:

Parker Solar Probe has successfully completed its second close approach to the Sun, called perihelion, and is now entering the outbound phase of its second solar orbit. At 6:40 p.m. EDT on April 4, 2019, the spacecraft passed within 15 million miles of our star, tying its distance record as the closest spacecraft ever to the Sun; Parker Solar Probe was traveling at 213,200 miles per hour during this perihelion.

The Parker Solar Probe mission team at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland scheduled a contact with the spacecraft via the Deep Space Network for four hours around the perihelion and monitored the health of the spacecraft throughout this critical part of the encounter. Parker Solar Probe sent back beacon status “A” throughout its second perihelion, indicating that the spacecraft is operating well and all instruments are collecting science data.

“The spacecraft is performing as designed, and it was great to be able to track it during this entire perihelion,” said APL’s Nickalaus Pinkine, Parker Solar Probe mission operations manager. “We’re looking forward to getting the science data down from this encounter in the coming weeks so the science teams can continue to explore the mysteries of the corona and the Sun.”

Parker Solar Probe montage. Credit: NASA/Johns Hopkins APL/Steve Gribben

** Will the Sun remain quiet or not? Bob Zimmerman reports on the latest sunspot activity and on predictions for the next phase of the solar cycle: Sunspot update March 2019: An upcoming Grand Minimum? | Behind The Black

Even though we are now deep into the beginning of what might become the first grand minimum in sunspot activity since the invention of the telescope, that does not mean the Sun has as yet stopped producing sunspots. Yesterday NOAA released its the monthly update of its tracking of the solar cycle, adding sunspot activity for March 2019 to its graph. Below is that graph, annotated by me to give it some context.

It shows the Sun with a slight burst in activity in March, suggesting that though we are now in the solar minimum that minimum still has the ability to produce sunspots.

** Sounding rockets produced a  spectacular sky show after releasing tracer gases. The goal of the NASA project is to help better understand the flow of charged particles in the earths magnetic fields at the poles: Two rockets dropped tracers into the northern lights and the result was glorious | Ars Technica

Late Friday night, two sounding rockets launched from a small spaceport in northern Norway. The two skinny rockets soared to an altitude of 320km, and along the way each released a visible gas intended to disperse through and illuminate conditions inside the aurora borealis. Some of the resulting images were stunning.

This NASA-funded AZURE mission, which stands for Auroral Zone Upwelling Rocket Experiment, is one of a series of sounding rocket missions launching over the next two years as part of an international collaboration known as “The Grand Challenge Initiative – Cusp.” The goal of these flights is to study the region where Earth’s magnetic field lines bend down into the atmosphere, and particles from space mix with those from the planet.

See also Sounding Rocket Mission Will Trace Auroral Winds | NASA.

April 8, 2019: The Auroral Zone Upwelling Rocket Experiment or AZURE mission was successfully conducted April 5 from the Andøya Space Center in Norway. The first Black Brant XI sounding rocket was launched at 6:14 p.m. EDT and flew to an altitude of 200 miles, followed by the launch of the second Black Brant XI at 6:16 p.m. EDT flying to an altitude of 202 miles. The initial assessment from the field showed that the rockets were launched into a good science event and ground based photos/data of the vapor releases were obtained from at least two locations.  Preliminary reports state that the scientist for the mission were very pleased with the results.

** The next Northrop-Grumman Cygnus cargo mission to the ISS will carry an array of experiments: Cygnus Carries Tech and Science Investigations to Space Station | NASA

A Northrop Grumman Cygnus spacecraft scheduled to liftoff on April 17 carries supplies and scientific experiments to the International Space Station. It uses a new late load capability that allows time-sensitive experiments to be loaded just 24 hours before liftoff. Previously, all cargo had to be loaded about four days prior to launch, creating challenges for some types of experiments.

The launch on the company’s Antares rocket departs from Pad-0A of the Mid-Atlantic Regional Spaceport (MARS) at NASA’s Wallops Flight Facility on Wallops Island, Virginia. This Cygnus mission is the 11th and final under Northrop’s Commercial Resupply Services (CRS)-1 contract with NASA; a CRS-2 contract begins with a cargo launch in the fall. Resupply missions from U.S. companies ensure NASA’s capability to deliver critical science research to the space station and significantly increase its ability to conduct new investigations in the only laboratory in space.

Continue to the article to see a list of the experiments.

====

Brief Answers to the Big Questions – Stephen Hawking

Astronomy

ESO: Optical interferometry reveals details of the atmosphere of an exoplanet

The latest report from ESO (European Southern Observatory):

GRAVITY instrument breaks new ground in exoplanet imaging
Cutting-edge VLTI instrument reveals details of a storm-wracked exoplanet
using optical interferometry

The GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) has made the first direct observation of an exoplanet using optical interferometry. This method revealed a complex exoplanetary atmosphere with clouds of iron and silicates swirling in a planet-wide storm. The technique presents unique possibilities for characterising many of the exoplanets known today. This artist’s impression shows the observed exoplanet, which goes by the name HR8799e. Credit: ESO/L. Calçada

The GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) has made the first direct observation of an exoplanet using optical interferometry. This method revealed a complex exoplanetary atmosphere with clouds of iron and silicates swirling in a planet-wide storm. The technique presents unique possibilities for characterising many of the exoplanets known today.

Aerial view of the observing platform on the top of Paranal mountain (from late 1999), with the four enclosures for the 8.2-m Unit Telescopes (UTs) and various installations for the VLT Interferometer (VLTI). Three 1.8-m VLTI Auxiliary Telescopes (ATs) and paths of the light beams have been superimposed on the photo. Also seen are some of the 30 “stations” where the ATs will be positioned for observations and from where the light beams from the telescopes can enter the Interferometric Tunnel below. The straight structures are supports for the rails on which the telescopes can move from one station to another. The Interferometric Laboratory (partly subterranean) is at the centre of the platform.

This result was announced today in a letter in the journal Astronomy and Astrophysics by the GRAVITY Collaboration [1], in which they present observations of the exoplanet HR8799e using optical interferometry. The exoplanet was discovered in 2010 orbiting the young main-sequence star HR8799, which lies around 129 light-years from Earth in the constellation of Pegasus.

 

Today’s result, which reveals new characteristics of HR8799e, required an instrument with very high resolution and sensitivity. GRAVITY can use ESO’s VLT’s four unit telescopes to work together to mimic a single larger telescope using a technique known as interferometry [2]. This creates a super-telescope — the VLTI  — that collects and precisely disentangles the light from HR8799e’s atmosphere and the light from its parent star [3].

The HR 8799 system harbors four super-Jupiters orbiting with periods that range from decades to centuries. HR 8799e is the innermost planet in this video. This footage consists of 7 images of HR 8799 taken with the Keck Telescope over 7 years. The video was made by Jason Wang, data was reduced by Christian Marois, and the orbits were fit by Quinn Konopacky. Bruce Macintosh, Travis Barman, and Ben Zuckerman assisted in the observations.

HR8799e is a ‘super-Jupiter’, a world unlike any found in our Solar System, that is both more massive and much younger than any planet orbiting the Sun. At only 30 million years old, this baby exoplanet is young enough to give scientists a window onto the formation of planets and planetary systems. The exoplanet is thoroughly inhospitable — leftover energy from its formation and a powerful greenhouse effect heat HR8799e to a hostile temperature of roughly 1000 °C.

This is the first time that optical interferometry has been used to reveal details of an exoplanet, and the new technique furnished an exquisitely detailed spectrum of unprecedented quality — ten times more detailed than earlier observations. The team’s measurements were able to reveal the composition of HR8799e’s atmosphere  — which contained some surprises.

“Our analysis showed that HR8799e has an atmosphere containing far more carbon monoxide than methane — something not expected from equilibrium chemistry,” explains team leader Sylvestre Lacour researcher CNRS at the Observatoire de Paris – PSL and the Max Planck Institute for Extraterrestrial Physics. “We can best explain this surprising result with high vertical winds within the atmosphere preventing the carbon monoxide from reacting with hydrogen to form methane.”

The team found that the atmosphere also contains clouds of iron and silicate dust. When combined with the excess of carbon monoxide, this suggests that HR8799e’s atmosphere is engaged in an enormous and violent storm.

“Our observations suggest a ball of gas illuminated from the interior, with rays of warm light swirling through stormy patches of dark clouds,” elaborates Lacour. “Convection moves around the clouds of silicate and iron particles, which disaggregate and rain down into the interior. This paints a picture of a dynamic atmosphere of a giant exoplanet at birth, undergoing complex physical and chemical processes.”

This result builds on GRAVITY’s string of impressive discoveries, which have included breakthroughs such as last year’s observation of gas swirling at 30% of the speed of light just outside the event horizon of the massive Black Hole in the Galactic Centre. It also adds a new way of observing exoplanets to the already extensive arsenal of methods available to ESO’s telescopes and instruments — paving the way to many more impressive discoveries [4].

Schematic lay-out of the VLT Interferometer. The light from a distant celestial objects enters two of the VLT telescopes and is reflected by the various mirrors into the Interferometric Tunnel, below the observing platform on the top of Paranal. Two Delay Lines with moveable carriages continuously adjust the length of the paths so that the two beams interfere constructively and produce fringes at the interferometric focus in the laboratory.

Notes

[1] GRAVITY was developed by a collaboration consisting of the Max Planck Institute for Extraterrestrial Physics (Germany), LESIA of Paris Observatory–PSL / CNRS / Sorbonne Université / Univ. Paris Diderot and IPAG of Université Grenoble Alpes / CNRS (France), the Max Planck Institute for Astronomy (Germany), the University of Cologne (Germany), the CENTRA–Centro de Astrofisica e Gravitação (Portugal) and ESO.

[2] Interferometry is a technique that allows astronomers to create a super-telescope by combining several smaller telescopes. ESO’s VLTI is an interferometric telescope created by combining two or more of the Unit Telescopes (UTs) of the Very Large Telescope or all four of the smaller Auxiliary Telescopes. While each UT has an impressive 8.2-m primary mirror, combining them creates a telescope with 25 times more resolving power than a single UT observing in isolation.

[3] Exoplanets can be observed using many different methods. Some are indirect, such as the radial velocity method used by ESO’s exoplanet-hunting HARPS instrument, which measures the pull a planet’s gravity has on its parent star. Direct methods, like the technique pioneered for this result, involve observing the planet itself instead of its effect on its parent star.

[4] Recent exoplanet discoveries made using ESO telescopes include last year’s successful detection of a super-Earth orbiting Barnard’s Star, the closest single star to our Sun, and ALMA’s discovery of young planets orbiting an infant star, which used another novel technique for planet detection.

This wide-field image shows the surroundings of the young star HR8799 in the constellation of Pegasus. This picture was created from material forming part of the Digitized Sky Survey 2. The location of HR 8799 is shown.

Links

====

Brief Answers to the Big Questions – Stephen Hawking

Astronomy, Exoplanets

Video: “The Golden Age of Exoplanet Exploration”

At a public seminar at NASA JPL, Jessie Christiansen and Karl Stapelfeldt of Caltech and NASA talked about the exoplanets discoveries made thus far and those to be made by new observatories:

Since the discovery of the first exoplanet orbiting a sun-like star in 1995, several thousand more have been discovered. We’ve peered into the atmospheres of some, and we’ve found whole families of planets orbiting strange stars — many in configurations starkly different from our own. We’ve learned a lot from NASA’s Kepler mission, which launched 10 years ago and ceased operations in November 2018. A new NASA planet-hunting spacecraft called TESS, which began science operations as Kepler was winding down, will give us thousands of new discoveries in the coming years. And the Spitzer Space Telescope has provided us valuable insights into what these worlds might be like. This show will look at the state of exoplanet science and give us a view of what future discoveries may be around the corner.

This National Geo video gives a brief overview of exoplanets and how they are found and studied:

====

Chasing New Horizons: Inside the Epic First Mission to Pluto

Astronomy

ESO: The Cosmic Bat of the Orion constellation

The latest ESO (European Southern Observatory) report:

A Cosmic Bat in Flight
ESO’s Cosmic Gems Programme captures the Cosmic Bat’s dusty clouds

Hidden in one of the darkest corners of the Orion constellation, this Cosmic Bat is spreading its hazy wings through interstellar space two thousand light-years away. It is illuminated by the young stars nestled in its core — despite being shrouded by opaque clouds of dust, their bright rays still illuminate the nebula. Too dim to be discerned by the naked eye, NGC 1788 reveals its soft colours to ESO’s Very Large Telescope in this image — the most detailed to date.

Hidden in one of the darkest corners of the Orion constellation, this Cosmic Bat is spreading its hazy wings through interstellar space two thousand light-years away. It is illuminated by the young stars nestled in its core — despite being shrouded by opaque clouds of dust, their bright rays still illuminate the nebula. Too dim to be discerned by the naked eye, NGC 1788 reveals its soft colours to ESO’s Very Large Telescope in this image — the most detailed to date.

ESOcast 195 Light: A Cosmic Bat in Flight | ESO

ESO’s Very Large Telescope (VLT) has caught a glimpse of an ethereal nebula hidden away in the darkest corners of the constellation of Orion (The Hunter) — NGC 1788, nicknamed the Cosmic Bat. This bat-shaped reflection nebula doesn’t emit light — instead it is illuminated by a cluster of young stars in its core, only dimly visible through the clouds of dust. Scientific instruments have come a long way since NGC 1788 was first described, and this image taken by the VLT is the most detailed portrait of this nebula ever taken.

The delicate nebula NGC 1788 is located in a dark and often neglected corner of the constellation Orion. Although this ghostly cloud is rather isolated from Orion’s bright stars, their powerful winds and light have a strong impact on the nebula, forging its shape and making it a home to a multitude of infant suns. This image from the Digitized Sky Survey 2 covers a field of view of 3 x 2.9 degrees, and shows that the Bat Nebula is part of much larger nebulosity.

Even though this ghostly nebula in Orion appears to be isolated from other cosmic objects, astronomers believe that it was shaped by powerful stellar winds from the massive stars beyond it. These streams of scorching plasma are thrown from a star’s upper atmosphere at incredible speeds, shaping the clouds secluding the Cosmic Bat’s nascent stars.

NGC 1788 was first described by the German–British astronomer William Herschel, who included it in a catalogue that later served as the basis for one of the most significant collections of deep-sky objects, the New General Catalogue (NGC) [1]. A nice image of this small and dim nebula had already been captured by the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory, but this newly observed scene leaves it in the proverbial dust. Frozen in flight, the minute details of this Cosmic Bat’s dusty wings were imaged for the twentieth anniversary of one of ESO’s most versatile instruments, the FOcal Reducer and low dispersion Spectrograph 2 (FORS2).

FORS2 is an instrument mounted on Antu, one of the VLT’s 8.2-metre Unit Telescopes at the Paranal Observatory, and its ability to image large areas of the sky in exceptional detail has made it a coveted member of ESO’s fleet of cutting-edge scientific instruments. Since its first light 20 years ago, FORS2 has become known as “the Swiss army knife of instruments”. This moniker originates from its uniquely broad set of functions [2]. FORS2’s versatility extends beyond purely scientific uses — its ability to capture beautiful high-quality images like this makes it a particularly useful tool for public outreach.

This image was taken as part of ESO’s Cosmic Gems programme, an outreach initiative that uses ESO telescopes to produce images of interesting, intriguing or visually attractive objects for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations, and — with the help of FORS2 — produces breathtaking images of some of the most striking objects in the night sky, such as this intricate reflection nebula. In case the data collected could be useful for future scientific purposes, these observations are saved and made available to astronomers through the ESO Science Archive.

Notes

[1] In 1864 John Herschel published the General Catalogue of Nebulae and Clusters, which built on extensive catalogues and contained entries for more than five thousand intriguing deep-sky objects. Twenty-four years later, this catalogue was expanded by John Louis Emil Dreyer and published as the New General Catalogue of Nebulae and Clusters of Stars (NGC), a comprehensive collection of stunning deep-sky objects.

[2] In addition to being able to image large areas of the sky with precision, FORS2 can also measure the spectra of multiple objects in the night sky and analyse the polarisation of their light. Data from FORS2 are the basis of over 100 scientific studies published every year.

This chart shows the location of the reflection nebula NGC 1788 in the constellation of Orion (The Hunter). The map includes most of the stars visible to the unaided eye under good conditions, and the region of sky shown in this image is indicated. Credit: ESO, IAU and Sky & Telescope

More information

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a Strategic Partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.

Links