Massive, Deep Deposits of Ice Found on Mars

From Astronomy[1]

Researchers studying the eroded edges of ridges on Mars have found that substantial deposits of water ice exist just a few feet below martian surface, reaching over 300 feet thick in some areas.

The Mars Reconnaissance Orbiter captured this astonishing image showing an avalanche of dusty snow racing down the weakened side of an eroded slope on Mars. In this image, the snow is made up of dry ice (frozen carbon dioxide); however, researchers recently found similar slopes elsewhere on Mars with massive deposits of pure water ice. (NASA/JPL-Caltech/University of Arizona)

Despite the fact that Mars has an atmosphere just 1% as dense as Earth’s, the surface of the Red Planet still has to deal with plenty of weathering and erosion. In 2008, researchers even captured a full-scale avalanche on Mars as it plunged down a 2,300-foot slope into a valley. These types of geological events often expose the structures beneath the martian surface, revealing layers of rock, dry ice, and even water ice.

In a study published in the journal Science[2], researchers using the Mars Reconnaissance Orbiter (MRO) investigated eight steep and eroded slopes (known as scarps) at various locations across Mars. At each of these locations, they found thick shelves of relatively pure water ice located as little as 3.3 feet (1 meter) below the planet’s surface. Furthermore, some of these massive ice deposits were found to be more than 330 feet (100 meters) thick.

While scientists have observed water ice on the surface of the Red Planet many times before, researchers rarely get a chance to learn this much about its layering, thickness, purity, and prevalence.

According to the research paper, “The ice exposed by the scarps likely originated as snow that transformed into massive ice sheets, now preserved beneath less than 1 to 2 [meters] of dry and ice-cemented dust or regolith near ±55° latitude.” In 2008, the Phoenix Mars lander discovered similar ice deposits along martian scarps, but they were found in regions much closer to the planet’s northern pole.

In this color-enhanced image of an eroding cliff (or scarp) on Mars taken from above, water ice is shown in blue. The top third of the image is the planet’s surface leading up to the cliff’s edge, while the bottom third is the valley below. (NASA/JPL/University of Arizona/USGS)

Since the ice deposits discovered in this study were found intact along the scarps’ steep, eroded slopes, the researchers believe the ice is “cohesive and strong.” Furthermore, the team found that the ice appears banded, showing layered variations in its blue color. This suggests that the massive ice deposits are composed of many distinct layers that have been squished together over time, preserving a record of Mars’ climate history. However, because there are few craters near these sites, the authors suggest the ice was formed relatively recently—in the past million years or so.

Although the massive ice deposits formed quickly (geologically speaking), the researchers say they also recede a tiny bit each summer. In one scarp, the team found that over the course of only three martian years, multiple meter-wide boulders dislodged themselves from the ice deposits, tumbling down into the valley below. Based on this, the researchers estimated the ice is retreating (horizontally) at a rate of a few millimeters each year. This is probably due to the exposed, solid ice sublimating into gas as it contacts the thin martian air.

The discovery of these large reservoirs of pure water ice adds yet another piece of evidence supporting the increasingly held theory that water ice not only exists on Mars, but also is surprisingly common. Although the ice could obviously be used as a source of water for future manned missions to Mars, scientists have a long way to go before then. However, with the Mars 2020 rover just a few years away, the discovery of eight more tantalizing sites ripe for investigation is still an exciting find.

[1] By Jake Parks in Astronomy (January 11, 2018), accessed January 19, 2018.

[2] Colin M. Dundas, Ali M. Bramson, Lujendra Ojha, James J. Wray, Michael T. Mellon, Shane Byrne, and Alfred S. McEwen, “Exposed Subsurface Ice Sheets in The Martian Mid-Latitudes.” Science (359, 6372, Jan 12, 2018, pp. 199-201)


Mysterious Radio Bursts

Mysterious Radio Bursts[1]

The Arecibo Observatory in Arecibo, P.R., measured a mysterious pulse of energy known as a fast radio burst, suggesting that the pulses may be emitted by black holes or neutron stars. Credit Xavier Garcia/Bloomberg, via Getty Images

Snap, crackle or pop?

Nature keeps coming up with new and baffling ways to blow things up.

Astronomers have been baffled lately by the mysterious pulses of cosmic energy known as fast radio bursts that seem to pepper the cosmos. In a few unpredictable milliseconds, they typically emit as much energy as the sun does in a day. About 30 of these objects have been discovered deep in space since the first was detected in 2007, all but one burping out a cataclysmic radio pulse exactly once and then disappearing into the night.

Only one burster, known as FRB121102, after the date it was discovered (Nov. 2, 2012), has repeated itself, hundreds of times now.

That allowed Shami Chatterjee of Cornell and his colleagues to track it to a galaxy 3 billion light years away. But that only deepened the mystery of the powers of these objects, and why none are closer to us.

Among the more out-there explanations proffered was that they are lasers propelling alien interstellar spacecraft. That is a scheme that Earthlings themselves are considering to launch a fleet of miniature space probes to Alpha Centauri later this century.

Alas for E.T., new observations have now debunked alien technology as the explanation for at least one source of a burst, according to a new paper in Nature[2] by a multinational crew of radio astronomers.

The Green Bank Telescope in Green Bank, W.Va., made measurements that assisted researchers in tracking down the origin of the FRB121102 burst. Credit Jim Lo Scalzo/European Pressphoto Agency

As monitored by the mighty 300-meter-diameter radio telescope at Arecibo Observatory in Puerto Rico and abetted by measurements at the Green Bank Telescope in Green Bank, W.Va., the signals from the repeating burster FRB110212, bore the marks of having been produced in a magnetic field at least thousands of times more powerful than normally seen in space.

Those fields and other details of the radio measurements point the finger at the usual suspects of cosmic violence—black holes or neutron stars, the shrunken dense corpses of dead stars, the authors say. Although the facts would imply that these pathological objects of fascination and dread are up to tricks that astrophysicists have not yet conceived.

“It’s a neat result,” Dr. Chatterjee wrote in an email [to Dennis Overbye]. “We’re doing remote sensing of the environment of the fast radio burst source at a distance of 3 billion light years!”

The key is that the radio waves were highly polarized, the light waves vibrating up and down in only one direction, as if viewed through powerful glare-reducing sunglasses. But each wavelength of light was vibrating at a different angle, a telltale sign of an effect called Faraday rotation, in which a magnetic field twists the orientation of electromagnetic waves as they pass through.

When the burst was emitted, Dr. Chatterjee explained, it was polarized with all the wavelengths of light lined up and marching in step. But as it traveled, the magnetic field twisted them apart.

One attractive explanation, he said, was that the bursts are produced by a neutron star near a massive black hole. Or an apocalyptically magnetized neutron star called a magnetar, blazing forth in a cloud within the blown-off remains of its former star.

“But it would have to be unlike anything else seen in our galaxy, by orders of magnitude,” Dr. Chatterjee said.

“So we can’t really rule out more exotic models, and theorists have a lot of those,” he added, and rattled off possibilities including the tubes of primordial energy called cosmic strings and the mysterious dark matter that makes up a quarter of the universe. “Because why not? It’s still a bit of a mystery.”

Snap, crack and pop indeed.

So it isn’t turning out to be a great year for E.T. — at least not so far.

Early in January, astronomers monitoring an enigmatic object known as “Boyajian’s Star,” after the astronomer Tabetha Boyajian, concluded that erratic and striking dips in its brightness were not caused by some gigantic alien construction project. [Note: this object is also called “Tabby’s Star.”]

The dips—much greater than would be expected for a planet—were discovered by a group of citizen astronomers known as the “Planet Hunters,” who were following up on results from the Kepler spacecraft. The discovery had elicited suggestions that the dips could be caused by the construction of a Dyson-like sphere, a shell that an advanced civilization might build around its star in order to capture all its energy.

But new observations by Dr. Boyajian[3], of Louisiana State University, and other astronomers of a recent dimming showed that the amount of dimming depended on the wavelength, or color, of the light observed, a classic indication that the obscuring material is not solid but most likely dust.

Now another fantasy of extraterrestrial engineering is biting the dust. Sorry, E.T.

[1] See Dennis Overbye, “Magnetic Secrets of Mysterious Radio Bursts in a Faraway Galaxy,” The New York Times (January 20, 2018). A version of this article appears in print on January 23, 2018, on Page D3 of the New York edition with the headline: Secrets of Mysterious Radio Bursts”.

[2] Michilli, D., A. Seymour, D. Whitlow. “An Extreme Magneto-Ionic Environment Associated with the Fast Radio Burst Soource FRB121102,” Nature (553, January 10, 2018, pp. 182-185)

[3] Boyajian, Tabetha S., et al. “The First Post-Kepler Brightness Dips of KIC 8462852,” arXiv:1801.00732 [astro-ph.SR]

Top 10 Astronomy News Stories for 2017

Monica Young, at Sky and Telescope has offered a list of the top 10 Astronomy news stories of 2017.[1]

It’s been said that the 20th century was the golden era of astronomy, with the 21st century belonging to biology. Well, astronomy isn’t willing to give up its mantle just yet. Multiple detections of gravitational waves, exoplanet discoveries, and the thrilling exploration of the outer solar system — not to mention the most-watched celestial event of the country — number among the year’s biggest astronomy news stories. Per our annual tradition, here’s a recap of an exciting year.

  1. LIGO & Virgo Detect Neutron-star Merger

Artist’s conception of two neutron stars at the moment of collision.
Dana Berry / SkyWorks Digital, Inc.

On October 16th astronomers announced that the LIGO and Virgo gravitational-wave detectors had “heard” the brief signal of a neutron star collision. But that wasn’t all. The radioactive fireball that resulted from the merger also released electromagnetic radiation — light — so that for the first time astronomers could study light and gravitational waves emitted from the same source. Almost 4,000 astronomers, a third of the astronomical community, were involved in the discovery and follow-up observations. The find has big implications for cosmology and stellar science alike: Astronomers have already eliminated wilder theories of dark energy and questioned the origin of some gamma-ray bursts.

  1. Black Holes Coalesce — Again!

The neutron-star merger wasn’t the only gravitational-wave source bagged this year. The LIGO and Virgo teams discovered three additional mergers of stellar-mass black holes in 2017, with announcements on June 1st, September 27th, and November 16th, bringing the total number of sources to six. The discoveries garnered three of LIGO’s fathers, Rainer Weiss, Kip S. Thorne, and Barry C. Barish, the Nobel Prize.

  1. Coast-to-Coast Total Solar Eclipse

Robert Ray / S&T Online Photo Gallery

You may have heard that a solar eclipse passed across America this summer — for the month of August, it was all anyone could talk about! The entire continental U.S. was treated to a partial solar eclipse, and totality cut through 12 states, bringing what is arguably the most awesome celestial experience you can have to millions of Americans. Even at its longest, totality was a brief 2 minutes and 40 seconds. But for all who saw it, it was worth it.

  1. Cassini’s Grand Finale at Saturn

The Cassini team has long known — and planned for — the spacecraft to end its mission by plunging into the planet it orbited for more than a decade. Program manager Earl Maize summed up Cassini’s demise perfectly: “Cassini is going out with an empty tank of gas at the very top of its game in a scientifically unexplored environment.” Indeed, the data collected during the Grand Finale orbits are still generating surprises.

Artist’s portrayal of ‘Oumuamua (1I/2017 U1)
ESO / M. Kornmesser

  1. `Oumuamua, the Interstellar Visitor

Observers have chronicled celestial visitors for centuries, but they’ve never seen one quite like this. The space rock dubbed `Oumuamua (1I/2017 U1) whipped 24 million kilometers from Earth on October 14th before anyone even noticed. Only several days later did the sky-scanning Pan-STARRS 1 telescope sweep up the object — fortunately, before it left the solar system.

Calculations show that the space rock originated from somewhere in the direction of the Lyra constellation, swung around the Sun, and is now heading back out of the solar system. It’s possible `Oumuamua has been traveling between the stars for billions of years before passing us by. But it’s left mysteries in its wake: New observations are showing it to be a strange little rock.

  1. Next Target for New Horizons Might Be a Binary . . . with a Moon

Artist’s concept of 2014 MU69

On January 1, 2019, New Horizons will speed by its next target in the outer solar system: 2014 MU69. Until then, the 27th-magnitude Kuiper Belt object remains undetected in all but the deepest observations. So New Horizons put together a recon mission to gather information via stellar occultations. Three stars briefly blinked out behind MU69 in June and July, although astronomers only captured two of the three tricky observations. They show that the object is irregularly shaped — probably a binary, two objects each 15-20 kilometers in diameter. More recently, new analysis of the data suggests that the binary has a companion — a small moon.

  1. Mysterious Fast Radio Burst Reveals Its Secrets

In 2007 astronomers discovered fast radio bursts (FRBs) —radio waves from an unknown origin that are so brief that some doubted their existence. What these bursts shared in common was a smear to their signal that indicated they’d traveled through the cosmos for a long time — and if they were so distant, their source must be powerful.

Tying these elusive signals to something astronomers could study remained out of reach until, in 2012, astronomers discovered one of these sources not like the others: most FRBs are single events, but FRB121102 repeated. And in January, for the first time, astronomers were able to trace this repeated source to its host galaxy: a star-forming dwarf galaxy. The discovery suggests FRB121102 is the signal of a newly formed neutron star.

  1. Juno at Jupiter

Enhanced-color image of Jupiter’s Great Red Spot
NASA / JPL-Caltech / SwRI / MSSS / Jason Major

NASA’s Juno just completed its ninth science pass of Jupiter, sweeping close above the Jovian cloudtops and continuing a mission that has given us a brand-new view of the king of planets. While the Jupiter Energetic Particle Detector Instrument (JEDI) radiometer probes the depths of the Great Red Spot, other measurements are delving into the planet’s core. The data so far suggests that the cartoon image shown of Jupiter in textbooks is wrong — rather than a small core of metallic hydrogen, the planet may have a “fuzzy” core that extends halfway to its surface. In the December issue, Fran Bagenal, who heads Juno’s plasma team, unfolds these and other results.

  1. TRAPPIST-1 Hosts Seven Earth-Size (But Probably Not Habitable) Planets

Imaginative look at TRAPPIST-1 system
NASA / JPL-Caltech

In February astronomers announced four more Earth-sized planets orbit TRAPPIST-1, a cool red dwarf star, bringing the total Earth-size planets in this system to seven. Three of them orbit in the star’s habitable zone, but with some speculation thrown in, all seven have the potential for liquid surface water.

Unfortunately, studies of the parent star show that its high-energy radiation might already have stripped the planets’ atmospheres, rendering them inhospitable to life.

  1. Tabby’s Star Dimmed — This Time While We Were Watching

When a citizen scientist first pointed out the bizarre behavior of a star in the Kepler field, KIC 8462852 (nicknamed Tabby’s Star), it took some time for astronomers to analyze the data and figure out just how strange this star really is. Its random, deep dives in brightness baffled explanation, and by the time Tabetha Boyajian (Louisiana State University) and colleagues were able to analyze the data, the star had already settled down, acting as if nothing had ever happened. Speculation ensued, but what astronomers really needed was to watch the star’s brightness dip in real-time.

This year, Tabby’s Star has finally obliged, and observatories all over the world have been following it. According to Boyajian, we can expect a paper with the full details soon.

The year ahead holds much more in store for us too. Expect to see additional gravitational-wave detections with the next LIGO-Virgo gravitational-wave observing run, and perhaps we’ll see the first-ever image of a black hole’s silhouette. A slew of space missions await, too.

It’s sure to be an exciting year!

[1] Monica Young, “Top 10 Astronomy News Stories for 2017,” Sky and Telescope (December 29. 2017).  Monica Young, a professional astronomer by training, is news editor of Sky & Telescope.

Fast Radio Bursts


For the first time ever, astronomers have captured an enormous radio wave burst in real time, bringing us one step closer to understanding their origins.[1]

These fleeting eruptions, called blitzars or FRBs (Fast Radio Bursts), are truly bizarre cosmic phenomena. In the span of a millisecond, they emit as much radiation as the Sun does over a million years. But unlike other super-luminous events that span multiple wavelengths—gamma ray bursts or supernovae, for example—blitzars emit all that energy in a tiny band of the radio light spectrum.

One of the most perplexing phenomena in astronomy has come of age. The fleeting blasts of energetic cosmic radiation of unknown cause, now known as fast radio bursts[2] (FRBs), were first detected a decade ago. At the time, many astronomers dismissed the seemingly random blasts as little more than glitches. And although key facts, such as what causes them, are still largely a mystery, FRBs are now accepted as a genuine class of celestial signal and have spawned a field of their own.[3]

The first FRB was co-discovered in 2007 by astronomer Duncan Lorimer[4] at West Virginia University. He found in archived pulsar data a 5-millisecond radio frequency burst that was so bright it couldn’t be ignored. Astronomers have since seen 25 FRBs. All are brief radio signals, lasting no more than a few thousandths of a second. They seem to come from sources across the sky and beyond our Galaxy. Some last longer than others, and the light from a few is polarized.

A discovery in 2016 caused further excitement. Astronomers reported[5] that they had found a repeating FRB—a surprise, because all the other signals had been one-off blips. And in January 2017, its origin was identified[6]: a faint, distant dwarf galaxy around 780 megaparsecs (2.5billion light years) away, in a star-forming region that also hums with a steady radio source.

The repeater has gone some way to focusing the FRB field, says Edo Berger, an astronomer at Harvard University in Cambridge, Massachusetts. Astronomers have now observed nearly 200 signals from it; details of 20 have been published. It bolsters the hypothesis that the signals are extragalactic, something most FRB researchers now agree on, and its location is reshaping theories about possible causes.

Dwarf galaxies host fewer stars than most, so tracking an FRB to one is surprising, says Berger. He thinks that the unusual environment is more than coincidence, and that FRBs may come from super-powerful magnetars—dense, magnetic stars thought to form after an abnormally massive explosion, such as an extremely energetic supernova. Studies suggest that such events seem to be more common in dim dwarf galaxies, he says. Others think the bursts might come from active galactic nuclei, regions at the centers of some galaxies that are thought to host supermassive black holes. Streams of plasma from these could comb nearby pulsars to produce FRBs, says Zhang, which could also explain a recent, although tentative, observation of a faint γ-ray burst coinciding with an FRB.

We are at the dawn of the fast radio burst era. For now, we will have to wait to see where this new cosmic mystery takes us.

[1] See Yvette Cendes, “Cosmic Firecrackers: The Mystery of Fast Radio Bursts,” Astronomy (46, 2, February 2018, pp. 20-23

[2] Elizabeth Gibney, “Why Ultra-Powerful Radio Bursts Are the Most Perplexing Mystery in Astronomy,” Nature News (534, 7609,, 28 June, 04 Rev July 2016). ( )

[3] See Elizabeth Gibney, “Astronomers Grapple with New Era of Fast Radio Bursts.” Nature News (543, 7643, 26 Feb 2016).

[4] Lorimer, D. R., M .Bailes., M. A McLaughlin, D. J. Narkevic, and F. Crawford, “A Bright Millisecond Radio Burst of Extragalactic Origin,” Science (318, 5851, 2 Nov 2007, pp. 777–780).

[5] Spitler, L. G. et al. ” A Repeating Fast Radio Burst,” Nature (531, pp.  202–205, 2 March, 2016).

[6] Chatterjee, S. et al. “A Direct Localization of a Fast Radio Burst And Its Host,” Nature (541, pp. 58–61, 5 January, 2017)

Arecibo Observatory Will Keep Scanning the Skies

Arecibo Observatory Will Keep Scanning the Skies[1]

Hurricane Maria caused havoc on Puerto Rico [September 19-20, 2017] , which contained the famous Arecibo Observatory. Luckily, the National Science Foundation (NSF) is looking for partners to continue funding the radio telescope. The NSF’s budget for Arecibo has diminished but hopes to transfer ownership to a third party such as a university.

There are options that include demolition for the observatory but NSF hopes “to collaborate with interested parties to maintain science-focused operations at the observatory with reduced agency funding”. This news excited NASA and many other institutions who hope to continue utilizing the observatory since its construction in 1960 as the second-largest radio telescope in the world.

Hurricane Maria caused minor damage to the Arecibo Observatory on 20 September to include blowing away a secondary antenna suspended on catenary wires above the central dish; electricity and communications were knocked out for a while. The NSF hopes to use any funds available to restore the functionality of the observatory prior to the damage caused by the hurricane. Arecibo has been used to conduct analysis on asteroids, planets, pulsars, galaxies, and dark matter, as well as sending/receiving signals to distant universes in hope of contact with extraterrestrial life. A recent objective for Arecibo was the triple asteroid, Florence, the asteroid(s) passed roughly 4 million miles from Earth on 1 September 2017, and interestingly Florence contained two companions or moons.

[1] Stephen Clark, “Arecibo Observatory Will Keep Scanning the Skies,” Astronomy Now (November 16, 2017), retrieved November 28, 2017, from

An Interstellar Interloper is Dashing Through our Solar System

An Interstellar Interloper is Dashing Through our Solar System[1]

Artist’s concept of interstellar asteroid 1I/2017 U1 (‘Oumuamua) as it passed through the solar system after its discovery in October 2017. The aspect ratio of up to 10:1 is unlike that of any object seen in our own solar system. Image credit: European Southern Observatory / M. Kornmesser


A cigar-like shaped asteroid was observed in October 2017 flying through our Solar System and is believed to have been formed from another star making it the “first confirmed interstellar asteroid” The asteroid was discovered by the University of Hawaii’s Pan-STARRS 1 telescope on Haleakala, Hawaii on 19 October, 2017 and within a couple of days, was determined to have originated from outside our Solar System. The asteroid was given the name 1I/2017 U1 and nicknamed ‘Oumuamua, it appears to have a reddish color and has a lengthened shape. The object is estimated to be at least a football field in length and thought to be 10 times longer than it is wide; this is not common within our Solar System and could have been traveling in space from another solar system for possibly a billion years. This asteroid was initially thought to be a comet but upon further investigations, no gas or dust was observed around it. Using European Southern Observatory’s Very Large Telescope in Chile, the origin of the asteroid was tried to be found. The asteroid was determined to come from the direction of Vega within the Lyra constellation but roughly 300,000 years ago the object came right through Vega leaving its origin still to be undetermined. The asteroid was closest to Earth on 14 October 2017 and will pass Jupiter in May 2018 to continue onwards to the constellation Pegasus.

Clark, S. (2017, November 22). An Interstellar Interloper is Dashing Through our Solar System. Retrieved November 28, 2017, from

[1] See Stephen Clark, “An Interstellar Interloper Is Dashing through Our Solar System,” Astronomy Now (February 23, 2018) accessed at February 28, 2018

Earth-Like Exoplanet

Closest Temperature World Orbiting Quiet Star Discovered[1]

Using the European Southern Observatory’s High Accuracy Radial velocity Planet Searcher (HARPS) at the La Silla Observatory in Chile, a team has discovered a red dwarf star “Ross 128” is orbited by another exoplanet roughly every 10 days. The exoplanet is thought to be around the same size as Earth to include having a similar surface temperature. The discovery of this planet is based on at least a decade of data reduction and analysis techniques using the HARPS which is known for its precision and has been deemed the name “best planet hunter of its kind”. Red dwarfs are common, coolest, and the faintest of stars in the Universe which makes them great targets for the search of other planets. Many scientists believe it is easier to find planets similar to Earth around red dwarfs instead of looking at stars such as the Sun. Ross 128 is interesting because in roughly 79,000 years it will be our nearest “stellar neighbor” even though it is currently 11 light-years away now. The Ross 128 is about 20 times closer to the red dwarf than the Earth is to the Sun but it is estimated Ross 128 receives about 1.38 times as much radiation as Earth does from the Sun with a surface temperature between -60° and 20°C.  The next questions to be answered will be found through a study of its composition, atmosphere, and the possibility of water.

[1] European Southern Observatory (ESO) press release. (2017, November 16). Closest Temperature World Orbiting Quiet Star Discovered. Retrieved November 28, 2017, from