Space News & Blog Articles

Humanity moved an asteroid on purpose for the first time in history. Juno flies past Jupiter’s moon Europa. A possible mission to boost Hubble, and a mysterious blob is orbiting Milky Way’s supermassive black hole.

Here’s a neat TLDR video version of Space Bites. So, you can just sit back, relax, and enjoy this week’s most important space and astronomy news.

DART Successfully Smashed Into Asteroid Dimorphos

Humanity avenged the dinosaurs this week, smashing the Double Asteroid Redirection Test (DART) into Dimorphos, the moon of Asteroid Didymos. NASA hosted a live stream the final hour before impact, showing the asteroid target growth in the spacecraft’s crosshairs until the rock-strewn surface filled the screen. We saw one final full frame of the surface of asteroid Dimorphos, then a partial frame showing the very last data the spacecraft could send home.

Telescopes worldwide tracked the event, and the wreckage was visible, even in smaller amateur telescopes. Over the coming weeks and months, we’ll find out if the mission was successful. Did DART change the orbit of Dimorphos enough to measure?

More about DART impact.

In a recent study published in Monthly Notices of the Royal Astronomical Society, an international team of researchers led by Stanford University have produced the first computer-generated 3D model of the Cat’s Eye Nebula, which unveiled a symmetric pair of rings that enclose the outer shell of the nebula. This study holds the potential for helping us better understanding the nebula’s makeup and how it formed, as the symmetric rings provides clues that they were formed from a precessing jet, which produces strong confirmation that a binary star exists at the nebula’s center.

The Cat’s Eye Nebula, also known as NGC 6543, is located approximately 3,000 light-years from Earth, and is one of the most breathtaking images of the night sky. Like most planetary nebulas, it was formed when the outer layer of gas is ejected by a dying solar-mass star. Images from the Hubble Space Telescope (HST) reveal a complex composition of arc-like filaments, knots, and spherical shells, which only adds to its beauty.

The mysterious structure of Cat’s Eye has dumbfounded scientists for years, as they couldn’t figure out how traditional theories of planetary nebula formation could explain its complex shape. Research in recent years demonstrated that precessing jets could act as shaping mechanisms in nebulae such as NGC 6543, but at the same time lacked a detail model to corroborate these claims.

That was until Ryan Clairmont, a prospective undergraduate at Stanford University, astronomy enthusiast, and lead author of the study, took the initiative to create a 3D structure of Cat’s Eye in hopes of explaining its unique shape that traditional astrophysics had trouble explaining. He enlisted the help of Dr. Nico Koning of the University of Calgary, who developed SHAPE, which is a 3D astrophysical modeling software that is appropriate for modeling planetary nebulae, and Dr. Wolfgang Steffen of the National Autonomous University of Mexico.

For the study, the researchers utilized spectral data from the San Pedro Martir National Observatory in Mexico to reassemble the nebula’s 3D structure. Combining this data with images from HST, Clairmont was able to build a novel 3D model of Cat’s Eye, demonstrating that high-density gas rings enveloped the nebula’s outer shell. The fact that the rings were almost perfectly symmetrical suggests they were formed by a jet, which is a high-density gas stream that is ejected from the nebula in opposite directions.

We recently examined how and why Jupiter’s moon, Europa, could answer the longstanding question: Are we alone? While this small icy world gives plenty of reasons to believe why we could—and should—find life within its watery depths, it turns out our solar system is home to a myriad of places where we might find life. Much like how the Voyager missions gave us the first hints of an interior ocean swirling beneath Europa’s outer icy shell, it was only fitting that Voyager 1 also gave us the first hints of the potential for life on Saturn’s largest moon, Titan, as well.

“Titan is fascinating because it is so far away from Earth, so cold, and made of such different materials on the surface that it should be impossible to understand,” says Dr. Jani Radebaugh, a Professor in the Department of Geological Sciences at Brigham Young University whose research focuses on Titan. “But we find that Earth-like landscapes are there in abundance – rivers, lakes, mountains, wind-swept deserts, and my favorite – giant dunes like in the Sahara Desert.”

Despite Voyager 1’s cameras being unable to penetrate Titan’s thick atmosphere, it successfully gathered data on Titan’s surface temperature and air pressure, with some scientists previously conjecturing that Titan might contain lakes of liquid hydrocarbons due to the moon’s extremely cold temperatures and abundance of methane. While this well-known component of carbon and hydrogen exists in a gaseous form here on Earth, methane can also exist in liquid form in extremely cold temperatures, much like Titan. Voyager also confirmed that Titan contained traces of ethane, propane, acetylene, and other organic molecules, with its atmosphere comprised largely of nitrogen. Organic molecules are considered the simple building blocks of life, which is why Titan is so intriguing for the field of astrobiology and finding life beyond Earth.

While NASA’s Cassini spacecraft provided us infrared images of Titan’s surface, which revealed hydrocarbon seas and moving sand dunes, it wasn’t until the European Space Agency’s (ESA) Huygens probe landed on the surface of Titan in January 2005 that we got our first up-close views of the surface of this mysterious moon. It was through these images that we confirmed evidence of recent surface liquid activity due to the abundance of rounded pebbles within the images.

Infrared composite image of Titan taken by Cassini in November 2015. (Credit: NASA/JPL/University of Arizona/University of Idaho)

Mars exploration has been ongoing for decades at this point, and some regions of the planet have become more interesting than others. Of particular interest is a basin known as Utopia Planitia. It was the site of the Viking-2 landing, one of the first-ever successful missions to Mars. From data collected during that mission, scientists developed a theory that the crater that formed Utopia might have been the site of an ancient ocean. New results from China’s Zhurong rover point to an even more exciting past – repeated flooding.

Zhurong has been exploring the red planet for a little over a year and has primarily been moving around Utopia Planitia. One of its instruments, a ground penetrating radar, is providing the world with the first data on the subsurface structure of Utopia since Viking-2 was shut down in 1980.

The picture that radar is painting is an interesting one. It appears that there are several layers beneath the surface of Utopia Planitia. The regolith, which is most commonly thought of as Martian dirt, only extends to about 10 meters below the surface.

Below that is where things get interesting – a paper just published in Nature by researchers at the Chinese Academy of Sciences points to several different sub-layers beneath the regolith. They also point to a potential cause – flooding.

That’s not to say that there is any active flooding going on. In fact, Zhurong found no evidence of liquid water anywhere within the basin’s top 80 meters of material. However, the layered structure the rover noticed could easily have been caused by repeated flooding events.

Kessler syndrome seems to be a growing fear for those interested in space exploration. The condition where numerous non-functional pieces of junk block access to orbit appears to be inching closer to reality, spurred on by weekly news reports of dozens of more satellites launching that will eventually become precisely that kind of obsolete space junk. But that won’t happen if the US’s Federal Communications Commission (FCC) has anything to do with it – a new rule the commission adopted will require companies to deorbit their unused satellites in less than five years after decommissioning.

By some arcane feature of the American bureaucracy, the FCC, which typically is thought of more as a regulator for cell phone wireless spectra and making sure that pacemakers aren’t interrupted by welding machines, is somehow responsible for the country’s satellite policies. Previously, the commission had ruled that satellites could stay in orbit for up to 25 years, and some had been grandfathered in. Some pieces of debris were still in orbit after being launched in the 1950s.

That will not stand with the dozens of new satellites being launched consistently. Superconstellations, such as Starlink’s planned potential 42,000 satellites, could pose an actual threat to human access to space, especially if some of them fail, as a non-insignificant number of Starlink satellites have. Worse yet, they could suffer an “unplanned catastrophic failure” that results in myriad smaller pieces of debris strewn through the satellite’s orbit. 

To put a stop to such a scenario, the FCC instituted a new rule that requires all companies that launch satellites to be able to deorbit them within five years of their decommissioning. There is a two-year grace period for this rule to take effect, most likely to allow companies time to integrate the new requirements into their existing projects and not burden any imminently launchable missions. In addition, there are some possible exceptions for particular science missions that might not be able to meet that requirement. 

Those requirements are not without controversy – some point to additional government red tape that could put some handcuffs on the rapidly expanding satellite industry. The FCC even hopes they are unnecessary, with one Commissioner stating that he hoped the rule would be “a largely unused backstop for best-in-class commercial practice.”

3D printing will be an absolutely critical technology as space exploration starts to take off. Initially, it will be impossible to individually manufacture every tool needed to create and sustain infrastructure in space. The only option will be to build some of those tools in space itself, in no small part, because it could potentially take months or even years to get to any area where the tools are manufactured. So any tool that can be created in situ is the best option available for early space explorers. Using materials like Martian regolith to 3D print those tools has long been an area of ongoing research. Now a team from Washington State University has successfully printed some tools using simulated Martian regolith, and they seem to work – up to a point.

The team, led by Professor Amit Bandyopadhyay of WSU’s Mechanical and Materials Engineering Department, used a powder-based 3D printing method to combine simulated Martian regolith. Martian regolith is a black, powdery substance designed to mimic materials found on the surface of the red planet with a powdered titanium alloy.

Combinations of materials ranging from only 5% regolith up to 100% regolith were tested. They were subjected to a sintering process that saw them heated to 2,000 degrees C and then allowed to cool while forming different shapes and sizes of solid material.

Testing the resultant ceramics was a mixed bag. Samples made of the 100% Martian regolith were brittle and developed cracks in their structure as part of the printing process. While those cracks would prove a deal-breaking for tool manufacturing, such cracks are relatively inconsequential for other use cases on the Martian surface, such as adding a layer of radiational protection to human habitats, which Dr. Bandyopadhyay and his team are quick to point out.

Lower concentrations of regolith (and consequently higher concentrations of titanium) performed better in terms of the material properties necessary for tool-making. In fact, the mixture of 5% regolith with 95% titanium actually resulted in superior physical properties to tools that were made with simply 100% titanium.

There’s a star system out there with three super-Earth planets and two super-Mercuries. Super-Earths are fairly familiar types of exoplanets, but super-Mercuries are rare. Those are planets with the same composition as our own Mercury, but larger and denser. Yet, here’s HD 23472, showing off two of eight known super-Mercuries in the galaxy.

A team of researchers at the Instituto de Astrofisica e Ciencias do Espaco in Portugal discovered these two dense inner planets. Their study is focused on small exoplanets and their compositions, and how position, temperature, and the properties of their stars affect them. The team chose HD 23472 as a candidate to study exoplanets and the transition between having or not having an atmosphere. It could be related to the evaporation of an atmosphere by irradiation from the parent star.

The discovery of two super-Mercuries in the system was unexpected, according to team leader Susana Barros. “The team found that this system is composed of three super-Earths with a significant atmosphere and surprisingly, two Super-Mercuries, which are the closest planets to the star,” she said.

This artist’s concept shows a five-exoplanet system similar to the one being studied. At HD 23472, however, there are two Super-Mercuries orbiting the star. Courtesy NASA Ames/Kepler/K2 Mission.

What’s a Super-Mercury and Why so Rare?

To get a handle on these rare planets, take a look at our own Mercury. It orbits closest to the Sun. So do these two planets. Structurally, it’s quite dense, as these super-Mercuries are. What we don’t know is their internal structure. If they’re like our Mercury, then they should each have a molten inner core as it does. In our Mercury, that core is surrounded by a solid iron sulfide outer core. A relatively thin crust made of silicate rocks lies at the top. Mercury also has a magnetic field. The temperature on its surface ranges up to 700 K (427 C), although the poles remain out of the sunlight and very cold.