Mercury likely has dense, thin crust, study reports

A new study shows that Mercury’s crust is roughly 25 percent thinner than previously believed.

Astronomers working at the University of Arizona’s Lunar and Planetary Lab have found new evidence that suggests Mercury’s crust is not as thick as previously thought, according to new research set to be published in the journal Planetary Science Letters.

To make this discovery, the team analyzed data from NASA’s Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) craft. That then enabled them to mathematically calculate the width of Mercury’s crust. Such calculations revealed that the rock is likely both thinner and more dense than previously thought.

Initially, scientists believed that Mercury’s crust measured 22 miles deep. However, the recent research shows that the crust is 16 miles thick. It is likely denser than aluminum as well.

“We know what minerals usually form rocks, and we know what elements each of these minerals contain,” said lead author Michael Sori, a researcher at the University of Arizona, in a statement. “We can intelligently divide all the chemical abundances into a list of minerals. We know the densities of each of these minerals. We add them all up, and we get a map of density.”

This finding is important because it gives credence to the theory that Mercury’s crust came about through volcanic activity. Even so, that does not explain how Mercury’s core — which measures 60 percent of the planet’s volume — is bigger than both the mantle and crust.

While the jury is still out on that, the team behind the research believes that Mercury’s thinness may be the result of massive impacts that stripped away many of its rock formations. There is also a chance solar winds may have taken away parts of the crust and left the planet with a larger core.

Either way, now that scientists are aware of the planet’s crust, they can get a better idea as to how it evolved or shifted over time. Many organizations around the world plan to follow up on the findings by taking a closer look into the distant planet.

For example, the European Space Agency’s BepiColombo mission — which will launch later this year — is set to land on the world in 2025.

“It’s been a long and occasionally bumpy road to this point, and there is still plenty to do until we are ready for launch,” said Ulrich Reininghaus, the BepiColombo project manager who was not involved in the research, according to Tech Times. “But we are extremely pleased to finally move our preparations to the launch site, and are grateful to everyone who has made this possible.”

Hubble images spiral galaxy two times the size of Milky Way

Milky Way’s “big sister” continues to grow and experience new star formation.

NASA’s Hubble Space Telescope (HST) has captured an image of a massive spiral galaxy, which is shaped like the Milky Way but twice its size.

Using its Wide Field Camera 3 (WFC3), the space telescope photographed NGC 6744, obtaining detailed images of the galaxy, which has a diameter of 200,000 light years, in comparison with the 100,000-light-year-wide Milky Way.

Located approximately 30 million light years from Earth in the constellation Pavo, NGC 6744 appears as a faint, extended object when viewed by most small telescopes. It is not visible to the naked eye.

“NGC 6744 is similar to our home galaxy in more ways than one,” a NASA statement notes.

It resembles the Milky Way in that it has a central core region made up largely of old yellow stars and dusty spiral arms further out that appear pink and blue. The pink areas are stellar nurseries, where star formation is underway, while the blue areas are regions filled with young stars.

Within the long, curved spiral arms are numerous stars, planets, gas, and dust.

The fact that star formation is still going on indicates the galaxy remains active. Scientists believe NGC 6744 is still growing.

Near the massive galaxy is a smaller, companion galaxy with a distorted shape, similar to the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way.

Although the feature is not visible in the Hubble images, scientists spotted a Type Ic supernova, caused by the death of a massive star, within NGC 6744 in 2005.

Installed in 2009, the WFC3 has given Hubble unprecedented depth and range. It has studied a wide range of phenomena, from star formation to remote galaxies, and has taken the majority of the telescope’s most iconic images over the last nine years.


NASA plans Moon-orbiting space station by mid-2020s

Project will be a joint effort with commercial spaceflight companies.

NASA hopes to place a small crewed space station in lunar orbit by the mid-2020s, as part of its effort to return astronauts to the Moon.

Titled The Lunar Orbital Platform-Gateway, the project will be built in a collaborative effort between the space agency and commercial companies, such as Moon Express.

One of five contenders for the now-canceled Google Lunar X Prize, Moon Express was founded in 2010 to mine lunar resources. Since then, it has focused on lowering costs for un-crewed lunar missions.

“What happened to the commercial launch industry is about to happen to the commercial lunar industry,” Moon Express CEO Bob Richards told USA Today. “I think there are very strong analogies between the two.”

Together with Moon Express, NASA hopes to land robotic spacecraft with scientific instruments on the Moon as soon as next year.

Astronauts on the new space station will not be able to land on the Moon until a lander is constructed. This could be done by other countries’ space agencies or by commercial companies, such as SpaceX and Blue Origin.

Michele Gates, director of Gateway’s power and propulsion program, said NASA is seeking input on design and construction of the space station from private spaceflight companies.

The power and propulsion program could also lead to better, high-rate communication between Earth and astronauts in deep space.

“We believe partnering with US industry for the power and propulsion element will stimulate advancements in commercial use of solar electric propulsion and also serve NASA exploration objectives. Our goal here is to gain input from industry on the draft solicitation to enable release of the final later this summer.

Several factors are driving the impetus to return to the Moon, including President Donald Trump’s stated desire to land astronauts there, the upcoming 50th anniversary of the Apollo 11 Moon landing, and the discovery of water sources on the lunar surface.

Having access to water would be a major boon to a space station, which could use it for everything from drinking water to rocket fuel.

Long-term goals for Gateway include not just exploration of the Moon but also of Mars, according to a NASA statement.

“Since the directive was issued in December to return to the Moon, the agency has been moving full-steam ahead with plans for robotic and human lunar exploration,” stated Jason Crusan, director of Advanced Exploration Systems at NASA Headquarters in Washington, DC.

Io may have another volcano

Astronomers believe a hotspot discovered on Jupiter’s moon Io may be the site of another volcano.

The NASA Juno spacecraft has potentially discovered a hidden volcano in Jupiter’s moon Io.

Juno is an important instrument that has made significant contributions to astronomy. It has spent nearly 150 million miles in Jupiter’s orbit since it first went up in 2016. Since then, the craft has taken pictures, recorded time-lapse photos, and made new discoveries.

The volcano on Io is the newest addition to that list.

Researchers working with NASA first took note of the potential formation when analyzing data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument. Study of the Io revealed a brand new heat source near its south pole.

Though astronomers are not sure what the heat source is, chances are that it is another volcano. Io — which is known as the most volcanically active body in the solar system — already has plenty, and the finding would further reinforce that title.

The newly discovered hotspot sits 200 miles from the nearest known heat signature. While there is a chance it is a previously known volcano that moved over time, more research needs to be done before any conclusions can be made.

“The new Io hotspot JIRAM picked up is about 200 miles (300 kilometers) from the nearest previously mapped hotspot,” said Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome, according to “We are not ruling out movement or modification of a previously discovered hot spot, but it is difficult to imagine one could travel such a distance and still be considered the same feature.”

NASA plans to follow up on their research in the coming months to see what else they can figure out about Io. They hope the Juno craft will give them more insight after the next flyby, which is set to take place in a few days.

“We are not ruling out movement or modification of a previously discovered hotspot, but it is difficult to imagine one could travel such a distance and still be considered the same feature,” added Mura, in a statement.

Viking landers may have burned organic molecules on Mars

Perchlorate in Martian soil may have exploded upon being heated, destroying organic molecules in the process.

NASA’s two Viking landers, the first spacecraft ever to touch down on the Martian surface, may have inadvertently destroyed organic molecules in soil samples collected following their 1976 landings.

Scientists long suspected the presence of organic molecules on Mars, as the planet is often bombarded with carbon-rich meteorites, and were surprised when neither Viking I nor Viking II found any on the Martian surface.

“It was just completely unexpected and inconsistent with what we knew,” noted NASA Ames Research Center planetary scientist Chris McKay.

In 2014, NASA’s Curiosity rover did find a variety of organic molecules on Mars. One of these is chlorobenzene, which is produced by the burning of carbon molecules with a salt known as perchlorate.  First discovered on Mars by NASA’s Phoenix lander in 2008, perchlorate explodes at very high temperatures.

Now, in a new study published in the Journal of Geophysical Research: Planets, a team of researchers propose the Viking landers, both of which heated up Martian soil during their searches for organics with their gas chromatograph-mass spectrometers (GCMS), inadvertently destroyed the very molecules they sought to find by causing perchlorates in the soil to explode.

Heating the soil was necessary in order to find any organic present.

If the scenario described above occurred, the chlorobenzene discovered by Curiosity could have been created as a byproduct of the burning of Martian soil by the Vikings.

Reviewing data sent back by the Vikings, study leaders McKay, Melissa Guzman of the LATMOS research center in France and their colleagues discovered that both landers detected chlorobenzene in their Martian soil samples.

While the chlorobenzene could have been produced by the burning of organic material in the samples, they could also have come from Earth via the Vikings’ equipment.

Scientists, including those who conducted this latest study, remain divided as to whether the Viking landers brought the organics from Earth or accidentally destroyed them during their Mars operations.


Delays in commercial crew program problematic for ISS

Government report advises NASA to develop contingency plans in the event deadlines aren’t met.

Both Boeing and SpaceX, companies with which NASA contracted to transport astronauts and supplies to the International Space Station (ISS) in 2019, could face delays of a year or more in obtaining agency certification for their vehicles, causing a gap in space station supply missions and astronaut transport.

Current schedules specify both companies will conduct un-crewed test flights in August of this year and crewed test flights shortly after, with Boeing’s scheduled for November and SpaceX’s for December.

Meeting these deadlines would enable both companies to be certified to fly astronauts to the ISS in early 2019–Boeing in January and SpaceX in February.

However, a report issued July 11 by the Government Accountability Office (GAO) expresses concern that both companies could miss the deadline for certification by at least a year. NASA’s contract with Russia for transportation of astronauts to and from the ISS via Soyuz capsules expires at the end of 2019, potentially leaving a gap with no supply missions or means of ferrying astronauts.

“Boeing and SpaceX continue to make progress developing a capability to fly to the ISS, but both have continued to experience delays. Additional delays could also disrupt US access to the ISS,” the report states.

NASA’s latest risk analysis predicts Boeing will be certified in December 2019 and SpaceX in January 2020. But these dates are estimates, and further delays could postpone both companies’ certifications to the fall of 2020.

Emphasizing the potential gap in access to the ISS, the GAO report advises NASA to develop a contingency plan for ISS access should the current deadlines not be met.

“If NASA does not develop options for ensuring access to the ISS in the event of further commercial crew delays, it will not be able to ensure that the US policy goal and objective for the ISS will be met,” the report notes.

NASA is already considering several options for dealing with the possible delays. One is extending Soyuz transport of astronauts until the end of 2020. Another is extending the crewed demonstration flights and prolonging astronauts’ stay on the space station by several months.

According to the GAO report, NASA has continued to insist the initial deadlines will be met by both Boeing and SpaceX even though the companies admit delays are likely.

NASA agreed to recommendations made in the report, including developing a contingency plan for ISS access by the end of this year, documenting its risk tolerance level for crew safety, and separating the job of managing commercial crew safety from that of independent safety oversight.

NASA releases new mosaics of Saturn moon Titan

Infrared instrument successfully peered through atmospheric haze to reveal surface features.

Using six separate images of Saturn’s largest moon Titan collected by the Cassini orbiter over 13 years, NASA released new mosaics  showing the moon in stunning detail.

The images were collected by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS) instrument, which observed in infrared wavelengths, enabling it to penetrate Titan’s hazy atmosphere, a feat not possible in visible wavelengths.

While this is not the first time VIMS images were used to create mosaics, it is the first time mission scientists produced mosaics that do not show the prominent seams that result from putting together images taken at different times, with a variety of lighting conditions and from a variety of angles.

By reanalyzing the VIMS data and processing the mosaics by hand, mission scientists successfully created the first seamless images of Saturn’s large 3,200-mile- (5,150-km-) wide moon, sometimes viewed as an analogue of early Earth.

Clearly visible in the colorful mosaics are Titan’s complex, varied surfaces, including seas of liquid hydrocarbons, icy deposits, and dunes that contain organic compounds.

“With the seams now gone, this new collection of images is by far the best representation of how the globe of Titan might appear to the casual observer if it weren’t for the moon’s hazy atmosphere,” mission scientists noted in a public statement.

Titan’s thick atmosphere, which contains a high percentage of nitrogen, conceals these diverse terrains. Small particles known as aerosols in the moon’s upper atmosphere scatter visible light, allowing viewers to see only a hazy orange sphere.

Atmospheric scattering and light absorption are much weaker in infrared wavelengths, which is why VIMS was able to obtain detailed photos of Titan’s surface.

Other than Earth, Titan is the only solar system object known to host liquids on its surface.

VIMS’s unique images of Titan will serve as a starting point for future missions observing the moon in the infrared in higher resolutions.

A proposed return to Titan, dubbed the Dragonfly mission, is one of two finalists in NASA’s New Frontiers program. To determine Titan’s habitability for life as we know it, Dragonfly would study the moon’s surface via a robotic minihelicopter.

If selected, Dragonfly will launch in 2025.

Cassini scientists also released a map of Titan showing latitudes, longitudes, and labeled surface features.