Planets – The Space Reporter

Auroras at Jupiter’s poles act independently

Researchers take advantage of rare opportunity to observe polar regions through Juno mission and space telescopes.

Auroras in Jupiter’s north and south polar regions act independently of one another, according to observations conducted by a study team using the European Space Agency’s (ESA) X-MM-Newton telescope and NASA’s Chandra X-ray Observatory.

Researchers at University College in London and at the Harvard-Smithsonian Center for Astrophysics led a study of high-energy X-ray auroras at both of Jupiter’s poles and were surprised to learn that unlike auroras on the poles of other planets, those at Jupiter’s poles do not mirror one another but pulse independently.

Activities of Earth’s north and south pole auroras mirror one another. Saturn does not appear to experience any X-ray auroras.

X-ray pulses at Jupiter’s south pole occur regularly every 11 minutes while those at its north pole are chaotic, with unpredictable increases and decreases in brightness.

“We didn’t expect to see Jupiter’s X-ray hot spots pulsing independently, as we thought their activity would be coordinated through the planet’s magnetic field,” explained study lead author William Dunn of both UCL Mullard Space Science Laboratory in the UK and the Harvard-Smithsonian Center for Astrophysics.

“We need to study this further to develop ideas for how Jupiter produces its X-ray aurora, and NASA’s Juno mission is really important for this.”

The researchers observed Jupiter using both space observatories in May and June of 2016 and in March 2007 to map the planet’s X-ray emissions and identify X-ray hot spots at its poles.

NASA’s Juno spacecraft, which arrived at Jupiter in 2016, does not have a science instrument capable of detecting X-rays; however, it is collecting other data at the polar regions that scientists hope to combine with the X-MM and Chandra data to better understand the planet’s auroras.

Scientists are fortunate that Juno is studying both of Jupiter’s poles at the same time, making it possible for them to compare activity at the poles with the giant planet’s complex magnetic interactions, emphasized study co-author Graziella Banduardi-Raymont of UCL Space and Climate Physics.

“If we can start to connect the X-ray signatures with the physical processes that produce them, then we can use those signatures to understand other bodies across the universe, such as brown dwarfs, exoplanets, or maybe even neutron stars,” Dunn stated.

One theory the researchers hope to test as they observe Jupiter’s polar activity over the next two years is that the northern and southern auroras form separately as a result of interactions between the planet’s magnetic field and the solar wind.

A paper discussing the findings has been published in the journal Nature Astronomy.

German scientists creating artificial Sun

Scientists in Germany are turning on what is being described as ‘the world’s largest artificial sun.’

The massive honeycomb-like structure, known as the ‘Synlight’, uses 149 large spotlights typically employed in cinemas, to simulate sunlight.

The scientists will focus the enormous array of xenon short-arc lamps on a single 8/8 inch spot.

The scientists from the German Aerospace Centre hope that by doing so, they will be able to reproduce the equivalent of 10,000 times the solar radiation that would normally shine on a surface the same size.

“If you went in the room when it was switched on, you would burn directly,” said Professor Bernard Hoffschmidt, a research director at the DLR, where the experiment is sheltered in a protective radiation chamber.

The experiment consumes as much electricity in four hours as a four-person household would in a year.

The furnace-like conditions that will be created by this energy will reach up to 5,432 Fahrenheit (3,000 degrees Celsius.)

The German government is one of the world’s biggest investors in renewable energy.

The scientists will attempt to find ways of tapping the vast amount of energy that hits the earth in the form of light from the sun.

One of the primary areas of research will be on how to produce hydrogen efficiently. This will be the first step towards creating artificial fuel for airplanes.

According to Professor Hoffschimdt, billions of tons of hydrogen would be needed to drive airplanes and cars on CO2-free fuel.

Hydrogen is considered a promising future source of fuel. This is because it does not produce carbon emissions, therefore not contributing to global warming.

Enceladus’s subsurface ocean harbors complex organic molecules

Saturn moon is now the only solar system location other than Earth to meet all requirements for microbial life.

Analysis of mass spectroscopy data returned by NASA’s Cassini spacecraft indicates Saturn’s moon Enceladus harbors complex organic molecules in its subsurface ocean, which are ejected through cracks in surface ice.

Cassini made several close flybys of Enceladus, one of the solar system’s top contenders for hosting microbial life, before the spacecraft was plunged into Saturn in September 2017. These flybys found evidence for a subsurface ocean above the moon’s rocky core and detected molecular hydrogen in plumes coming from that ocean.

Scientists believe molecular hydrogen is produced by geochemical interactions between water and rocks in hydrothermal environments, according to a paper on the findings published in the journal Nature.

“Hydrogen provides a source of chemical energy supporting microbes that live in the Earth’s oceans near hydrothermal vents. Once you have identified a potential food source for microbes, the next question to ask is, ‘what is the nature of the complex organics in the ocean?’ This paper represents the first step in that understanding–complexity in the organic chemistry beyond our expectations!” stated Hunter Waite of the Southwest Research Institute (SwRI), who served as principal investigator for Cassini’s Ion and Neutral Mass Spectrometer (INMS).

Both INMS and Cassini’s Cosmic Dust Analyzer (CDA) measured the contents of Enceladus’s plumes and of material in Saturn’s E ring, which is composed of ice grains from those plumes.

“Previously, we’d only identified the simplest organic molecules containing a few carbon atoms, but even that was intriguing,” Christoper Glenn, also of SwRI and a specialist in extraterrestrial chemical oceanography, noted. “Now, we’ve found organic molecules with masses above 200 atomic mass units. That’s over 10 times heavier than methane. With complex organic molecules emanating from its liquid water ocean, this moon is the only body besides Earth known to simultaneously satisfy all of the basic requirements for life as we know it.”

By working together, each with their own data set, the CDA and INMS teams achieved a better understanding of the organic chemistry in Enceladus’s ocean than either of the teams would have done with just their own data set, Glenn noted.

In their paper, the researchers recommend a future mission fly through Enceladus’s plumes and use a high-resolution mass spectrometer to analyze the complex organic molecules, with the goal of learning the process by which they formed.

Cyanobacteria study provides insight into future Mars colonization

Bacteria that conduct photosynthesis could provide human colonists with breathable air on other worlds.

A study at the Australian National University (ANU) that subjected cyanobacteria to inhospitable conditions is providing scientists with important insights into future human colonization of Mars.

Cyanobacteria are microbes that obtain their energy through photosynthesis and produce oxygen. One of the largest groups of bacteria on Earth, they have been around for more than 2.5 billion years.

Capable of adapting to harsh environments, cyanobacteria have been found in Antarctica, the Mojave Desert, and even the outside of the International Space Station (ISS).

Elmars Krausz of ANU suggested future human colonists on Mars and other solar system worlds could use cyanobacteria adapted to low-light environments to produce oxygen they could breathe and create a biosphere, an area where life could survive.

“This might sound like science fiction, but space agencies and private companies around the world are actively trying to turn this aspiration into reality in the not-too-distant future. Photosynthesis could theoretically be harnessed with these types of organisms to create air for humans to breathe on Mars,” Krausz said.

One particular type of chlorophyll, known as “red” chlorophyll, plays a key role in driving photosynthesis in low-light environments.

“Low-light adapted organisms, such as the cyanobacteria we’ve been studying, can grow under rocks and potentially survive the harsh conditions on the Red Planet,” he noted.

Through their pigments, “red” chlorophylls produce a signature fluorescence that colonizers of other worlds could use to track organisms indigenous to those worlds, stated Jenny Morton of ANU’s Research School of Chemistry.

Using a unique optical spectrometer along with computer modeling, the research team focused on better understanding the role of “red” chlorophylls in the process of photosynthesis.

“This work redefines the minimum energy needed in light to drive photosynthesis,” she added.

In experiments, organisms adapted to low-light environments died when exposed to full sunlight.

“All photosynthetic organisms, such as coral reefs, suffer severe environmental stresses from high temperatures, high light levels, and ultraviolet light, so this research helps scientists to better understand these limits,” Morton explained.

Findings of the study have been published in the journal Science.

Scientists image exoplanet in process of formation

Direct observation of baby planets will provide scientists with new insight into poorly understood planet formation process.

Scientists have captured the first ever image of a baby exoplanet in the process of forming within the protoplanetary disk of gas and dust surrounding its parent star.

Using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile, researchers obtained a clear image of the forming planet in orbit around the 5.4-million-year-old dwarf star PDS 70, approximately 370 light years from Earth.

SPHERE is an exoplanet-hunting instrument that acts as a coronagraph, which blocks the light of stars, enabling scientists to detect dim orbiting planets.

The newborn gas giant, known as PDS 70b, can be seen in the image as a bright point located to the right of the blocked-out star.

“These disks around young stars are the birthplaces of planets, but so far only a handful of observations have detected hints of baby planets in them,” said study leader Miriam Keppler of the Max Planck Institute for Astronomy in Heidelberg, Germany, in a public statement.

“The problem is that, until now, most of these planet candidates could just have been features in the disk.”

She and her colleagues photographed the forming planet after studying current and archival observations of the star via the VLT and an instrument at Hawaii’s Gemini Observatory.

According to the research team’s analysis, the planet is between two and three times larger than Jupiter and hotter than any planet in our solar system, with an estimated surface temperature of 1,800 degrees Fahrenheit (1,000 degrees Celsius).

Although it is extremely hot, PDS 70b orbits its star at a distance of 1.9 billion miles (three billion km), approximately the distance at which Uranus orbits our Sun.

Its high temperature is normal for a newborn gas giant even at such a great distance, as very young planets retain high levels of heat left over from their formation processes.

Observing a planet in the process of forming around a young star provide scientists with crucial insights into the planet formation process, noted Andre Muller, also of the Max Planck Institute for Astronomy, who led a second study on the star and planet.

“Kepler’s results give us a new window onto the complex and poorly understood early stages of planetary evolution,” he said.

Both Keppler’s study and Muller’s study have been published in the journal Astronomy and Astrophysics.

Ancient volcanoes formed Mars’s Medussae Fossae region

Volcanic eruptions could have warmed Mars enough for its surface to have supported liquid water.

Mars’s Medussae Fossae Formation, a region near the Martian equator composed of eroding sediments, may have been formed by ancient volcanic eruptions more than three billion years ago.

Composed of soft rock, this area, which was imaged by NASA’s Mars Reconnaissance Orbiter (MRO) in infrared wavelengths, is a massive region composed of ridges, valleys, and mesas. It has been described by NASA scientists as “an enigmatic pile of eroding sediments.”

First discovered during the 1960s by NASA’s Mariner spacecraft, Medussae Fossae and its exotic terrain and soft rock puzzled scientists, who were unable to determine whether it was created by wind, ice, water, or volcanoes.

Now, using MRO data, researchers at Johns Hopkins University in Baltimore measured the terrain’s density and found its porous surface to have likely been formed by explosive volcanic deposits rather than by ice deposits.

“The eruptions that created the deposit could have spewed massive amounts of climate-altering gases into Mars’s atmosphere and ejected enough water to cover Mars in a global ocean,” said Lujendra Ojha of Johns Hopkins University.

Medussaa Fossae is the largest known explosive volcanic deposit in the solar system, about 100 times more massive than the largest explosive volcanic deposit on Earth.

Gases emitted during the ancient eruptions could have warmed the planet enough for liquid water to have existed on the Red Planet’s surface. However, they also would have changed Mars’s atmosphere and surface by spewing hydrogen sulfide and sulfur dioxide, both of which are toxic gases.

Since the ancient eruptions, as much as half of the original rock at the site has eroded away, leaving behind the ridges and valleys.

“Future gravity surveys could help distinguish between ice, sediments, and igneous rocks in the upper crust of the planet,” noted Kevin Lewis, also of Johns Hopkins University.

Sedimentary rocks are deposited and solidify in layers and are usually transported by water and wind. Igneous rocks are formed when molten magma brought by volcanoes solidifies.

These findings are evidence that Mars’s interior is significantly more complex than scientists initially thought.

“Given the sheer magnitude of this deposit, it really is incredible because it implies that the magma was not only rich in volatiles and also that it had to be volatile-rich for long periods of time,” Ojha stated.

Findings of the study have been published in the Journal of Geophysical Research: Planets.

Mars’ oceans formed much earlier than previously believed

A new study gives compelling evidence that Mars once had a series of ancient oceans.

Mars’ ancient, now dried up oceans were older and much more shallow than previously believed, according to new research published in the journal Nature.

The study comes from researchers at the University of California, Berkeley, who connected the existence of Mars’ early oceans to the rise of our solar system’s largest volcanic system, Tharsis. That link is important because it suggests that global warming allowed liquid water to exist on the Red Planet.

In the new study, the team built a model that helps explain how water first came to the Red Planet. They believe the oceans formed 3.7 billion years ago, which puts them right before or at the same time as Tharsis. As the mountains were much smaller back then, they did not disrupt the planet as much as they did later on. That means the seas would have been relatively shallow, holding just half the water previous estimates assumed.

“The assumption was that Tharsis formed quickly and early, rather than gradually, and that the oceans came later,” explained study co-author Michael Manga, a professor at the University of California, Berkeley, according to Phys.org. “We’re saying that the oceans predate and accompany the lava outpourings that made Tharsis.”

The team’s research showed that Tharsis spewed gas into the atmosphere, a process that caused the global warming that created liquid water. The volcanic eruptions also generated channels that allowed underground water to reach the surface and fill the northern plains.

While some people are skeptical that Mars once had oceans, this research gives compelling evidence for the bodies of water. In addition to the research, scientists also found a series of irregular shorelines that suggest the volcano system depressed and deformed the land as it grew. Such a process may have created natural irregularities in rock height, especially if the oceans formed during Tharsis’ early years.

Though more work needs to be done, this research is a good start to understanding Mars’ oceans. The team plans to continue mapping and dating to see what else they can discover about the Red Planet’s past, and they hope NASA’s next Mars lander, InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) will help them in such endeavors.

“It could potentially detect the presence of subsurface frozen water, which could be a remnant of a past ocean,” said lead author Robert Citron, a planetary scientist at the University of California, Berkeley, according to Space.com.

Up to 35 percent of exoplanets may be ocean worlds

Temperatures and pressures of these worlds may not be conducive to harboring life.

Somewhere between 30 and 35 percent of all exoplanets may be ocean worlds two to four times the size of Earth, according to a team of scientists who presented their findings at the 2018 Goldschmidt Conference of the Geochemical Society.

The researchers analyzed data returned by NASA’s Kepler Space Telescope and Gaia mission and determined that many super-Earths, planets several times larger than our own, likely have compositions that are up to 50 percent water. In contrast, Earth’s composition is just 0.02 percent water.

Two types of super-Earths were identified in the study. Those with 1.5 times Earth’s radius or less are likely to be rocky while those with 2.5 times Earth’s radius are likely to be icy like Uranus and Neptune in our solar system.

Large super-Earths likely have water vapor atmospheres and surface oceans with extreme pressures, whose temperatures may range between 390 and 930 degrees Fahrenheit (200 and 500 degrees Celsius). Structurally, they may resemble gas giants, with cores far beneath their dense atmospheres.

In spite of having high amounts of water, the latter group of planets are not likely to be habitable.

“It was a huge surprise to realize that there must be so many water worlds, said Li Zeng of Harvard University, who led the study.

“This is water, but not as commonly found here on Earth. Their surface temperature is expected to be in the 200 to 500 degree Celsius range. Their surface may be shrouded in a water-vapor-dominated atmosphere, with a liquid water layer underneath. Moving deeper, one would expect to find this water transforms into high-pressure ices before reaching the solid, rocky core,” Zeng said.

He acknowledged that life could develop in layers close to these planets’ surfaces if their pressures, temperatures, and chemical conditions are just right.

The larger water worlds likely formed in processes similar to those that formed the cores of Uranus and Neptune, Zeng added.

NASA’s Transiting Exoplanet Survey Satellite (TESS), which launched earlier this year, and the James Webb Space Telescope (JWST), now scheduled for launch in 2021, will likely find many more water worlds, he noted. Discoveries by space observatories will be followed by ground-based spectroscopic observations.

JWST will enable scientists to identify the components in exoplanets’ atmospheres.

Scientists compute exoplanet’s mass using star-mapping satellite data

Hipparcos and Gaia measurements help scientists weigh extremely young exoplanet.

Using data collected by the European Space Agency’s (ESA) star-mapping satellites Hipparcos and Gaia, a team of researchers successfully calculated the mass of a baby exoplanet discovered in 2008.

Beta Pictoris b, a gas giant discovered by the European Southern Observatory’s (ESO) Very Large Telescope (VLT) in Chile, is a gas giant of 9-13 Jupiter masses orbiting the second brightest star in the constellation Pictor.

Hipparcos observed the Beta Pictoris system 111 times between 1990 and 1993. Gaia, launched in 2013, imaged the system 30 times since it began operating 22 months ago with the goal of looking at more than one billion stars in the Milky Way.

Beta Pictoris and its planet are approximately 20 million years old, making them 225 times younger than our solar system. Such young systems can be difficult to study because their stars are very hot, pulsate, and rotate very fast.

“In the Beta Pictoris system, the planet has essentially just formed. Therefore, we can get a picture of how planets form and how they behave in the early stages of their evolution,” said Ignas Snellen of Leiden University in the Netherlands.

Scientists typically measure a star’s radial velocity, the speed at which it regularly moves toward and away from Earth, to estimate the masses of planet(s) orbiting it. But this method works largely for older systems, where planet formation is complete.

An upper limit for Beta Pictoris b’s mass was established through the radial velocity method. Snellen and Anthony Brown, also of Leiden University, then studied measurements of the system taken by Hipparcos and Gaia, which gave them the exact position of the star as well as its motions over time.

“The star moves for different reasons. First, the star circles around the center of the Milky Way, just as the Sun does. That appears from the Earth as a linear motion projected on the sky. We call it proper motion. And then, there is the parallax effect, which is caused by the Earth orbiting around the Sun. Because of this, over the year, we see the star from slightly different angles,” Snellen explained.

Tiny wobbles in a star’s path are caused by the gravitational tugs of orbiting planets.

“We are looking at the deviation from what you would expect if there was no planet, and then we measure the mass of the planet from the significance of this deviation. The more massive the planet, the more significant the deviation,” Brown stated.

Doing this requires observation of a star over long periods of time, he added.

“Now, by combining Gaia and Hipparcos and looking at the difference in the long term and the short term proper motion, we can see the effect of the planet on the star.”

A paper on the study’s findings has been published in the journal Nature Astronomy.

Long lunar eclipse coincides with Mars opposition

Event will be streamed live online for those in areas where eclipse won’t be visible.

In an unusual astronomical coincidence, the 21st century’s longest total lunar eclipse will occur on the same night as Mars’s opposition, and both reddish objects will appear in the same part of the sky.

A planet is described as being in opposition when it and the Earth are on opposite sides of the Sun. Full Moons occur when the Moon is in opposition to the Earth. Objects in opposition rise at sunset and remain visible all night, then set at sunrise.

This particular Mars opposition is occurring when the Red Planet is closest to the Earth, so Mars will be at its largest apparent size when viewed through a telescope and will also be significantly brighter than usual.

Both the lunar eclipse and the Mars opposition will occur on Friday, July 27. Just four days later, Mars will be closest to the Earth, at a distance of 35.8 million miles (57.6 million km). An opposition in which a planet is also at its closest point to the Sun is known as a “perhihelic opposition.”

Because the Red Planet has an elliptical orbit, its distance from Earth ranges from a minimum of 34.6 million miles (55.8 million km) to a maximum of 140 million miles (225 million km). In 2003, the two planets came within 34.6 million miles of each other, the closest they had been in 60,000 years.

Friday’s total lunar eclipse will be visible to observers in Africa, the Middle East, southern Asia, Europe, South America, and Australia. Its total phase, during which the Moon appears red or orange, will last an hour and 43 minutes. From beginning to end, including the partial phases, the entire eclipse will last for almost four hours.

The Moon’s reddish color during the total phase of an eclipse is caused by the scattering of sunlight through Earth’s atmosphere. Because the atmosphere does more scattering of shorter light wavelengths, such as green and blue, longer wavelengths, such as red, become most visible.

During this particular eclipse, the Moon will travel through the center of Earth’s umbra, the darkest part of its shadow. It will also be at apogee, the furthest point in its orbit from the Earth, and will therefore take longer to pass through Earth’s shadow. These two phenomena are the reasons why this eclipse will be so long.

Although the eclipse will not be visible from North America, it will be livestreamed online by the website Time and Date Live, Slooh, and Space.com.

Slooh will also host a live cast on the Mars opposition on Thursday night, July 26. Unlike the lunar eclipse, Mars, like the ordinary full Moon, will be visible all night everywhere in the world barring obscuration by clouds.