Phosphorus, present in our DNA and cell membranes, is an essential element for life as we know it. But how it arrived on the early Earth is something of a mystery. Astronomers have now traced the journey of phosphorus from star-forming regions to comets using the combined powers of ALMA and the European Space Agency’s probe Rosetta. Their research shows, for the first time, where molecules containing phosphorus form, how this element is carried in comets, and how a particular molecule may have played a crucial role in starting life on our planet.
“Life appeared on Earth about 4 billion years ago, but we still do not know the processes that made it possible,“
says Víctor Rivilla, the lead author of a new study published today in the journal Monthly Notices of the Royal Astronomical Society. The new results from the Atacama Large Millimeter/Submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, and from the ROSINA instrument on board Rosetta, show that phosphorus monoxide is a key piece in the origin-of-life puzzle.
With the power of ALMA, which allowed a detailed look into the star-forming region AFGL 5142, astronomers could pinpoint where phosphorus-bearing molecules, like phosphorus monoxide, form. New stars and planetary systems arise in cloud-like regions of gas and dust in between stars, making these interstellar clouds the ideal places to start the search for life’s building blocks.
The ALMA observations showed that phosphorus-bearing molecules are created as massive stars are formed. Flows of gas from young massive stars open up cavities in interstellar clouds. Molecules containing phosphorus form on the cavity walls, through the combined action of shocks and radiation from the infant star. The astronomers have also shown that phosphorus monoxide is the most abundant phosphorus-bearing molecule in the cavity walls.
After searching for this molecule in star-forming regions with ALMA, the European team moved on to a Solar System object: the now-famous comet 67P/Churyumov–Gerasimenko. The idea was to follow the trail of these phosphorus-bearing compounds. If the cavity walls collapse to form a star, particularly a less-massive one like the Sun, phosphorus monoxide can freeze out and get trapped in the icy dust grains that remain around the new star. Even before the star is fully formed, those dust grains come together to form pebbles, rocks and ultimately comets, which become transporters of phosphorus monoxide.
ROSINA, which stands for Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, collected data from 67P for two years as Rosetta orbited the comet. Astronomers had found hints of phosphorus in the ROSINA data before, but they did not know what molecule had carried it there. Kathrin Altwegg, the Principal Investigator for Rosina and an author in the new study, got a clue about what this molecule could be after being approached at a conference by an astronomer studying star-forming regions with ALMA:
“She said that phosphorus monoxide would be a very likely candidate, so I went back to our data and there it was!”
This first sighting of phosphorus monoxide on a comet helps astronomers draw a connection between star-forming regions, where the molecule is created, all the way to Earth.
“The combination of the ALMA and ROSINA data has revealed a sort of chemical thread during the whole process of star formation, in which phosphorus monoxide plays the dominant role,”
says Rivilla, who is a researcher at the Arcetri Astrophysical Observatory of INAF, Italy’s National Institute for Astrophysics.
“Phosphorus is essential for life as we know it,” adds Altwegg. “As comets most probably delivered large amounts of organic compounds to the Earth, the phosphorus monoxide found in comet 67P may strengthen the link between comets and life on Earth.”
This intriguing journey could be documented because of the collaborative efforts between astronomers.
“The detection of phosphorus monoxide was clearly thanks to an interdisciplinary exchange between telescopes on Earth and instruments in space,”
Leonardo Testi, ESO astronomer and ALMA European Operations Manager, concludes:
“Understanding our cosmic origins, including how common the chemical conditions favourable for the emergence of life are, is a major topic of modern astrophysics. While ESO and ALMA focus on the observations of molecules in distant young planetary systems, the direct exploration of the chemical inventory within our Solar System is made possible by ESA missions, like Rosetta. The synergy between world leading ground-based and space facilities, through the collaboration between ESO and ESA, is a powerful asset for European researchers and enables transformational discoveries like the one reported in this paper.”
** 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:
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.
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.
** 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.
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.
** 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.
[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.
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.
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.
** 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.
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.
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.
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,”
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.