Space News & Blog Articles

Back in 2008, astronomers made a big announcement: for the first time, they had taken pictures of a multi-planet solar system, much like ours, orbiting another star. At the time, the star system, named HR8799 was known to have three planets, but follow-up observations a year later revealed a fourth world.

Astronomers have continued to watch this intriguing star system, and now, using observations from the last 12 years, astrophysicist Jason Wang has put together a time lapse video showing the orbital motions of the four planets.

“Astronomical events either happen too quickly or too slowly to capture in a movie,” said Wang.” But this video shows planets moving on a human time scale. I hope it enables people to enjoy something wondrous.”

The dusty young star HR8799 ch is 140 light years away and about 1.5 times the size of our Sun. Even more intriguing is that HR8799 is visible to the naked eye. It has a magnitude 5.96 and it is located inside the western edge of the great square of Pegasus almost exactly halfway between Scheat and Markab.

The planets were imaged using high-contrast, near-infrared adaptive optics observations with the Keck and Gemini telescopes. In a press release from Northwestern University, Wang said he was instantly fascinated by the system when the news broke in 2008, and has been watching it ever since. He and his colleagues applied for time on the W. M. Keck Observatory, located on the top of Mauna Kea in Hawaii, to observe the system each year.

In a recent study scheduled to be published in the journal Icarus in March 2023, a team of researchers led by the Southwest Research Institute (SwRI) modeled a potential correlation between an ancient freezing ocean with cryovolcanic flows and surface canyons on Pluto’s largest moon, Charon. Their hypothesis was that when Charon’s interior ocean froze long ago, the significant stress put on the icy outer shell from the addition of more ice to the bottom of the existing shell could have been responsible for the cryovolcanic flows on the surface.

In the end, the researchers found a freezing interior ocean was likely not responsible for Charon’s cryovolcanic flows due to the ice shell needing to be much thinner than indicated by current models. But if an interior ocean isn’t responsible for Charon’s cryovolcanic flows, then what could be responsible?

“My best guess is that Charon’s thermal evolution and geologic processes created pockets of melt within the ice shell that eventually migrated to the surface,” Dr. Alyssa Rhoden, who is a Principal Scientist at SwRI and lead author of the study, recently told Universe Today. “On moons like Europa, we think of areas with a high concentration of salt, which can affect the melting temperature and density of ice in a local region. On Charon, there are also nitrogen-bearing compounds, like ammonia, that can affect how melt forms and moves through the ice shell.

“It is also possible that the flows were made of oceanic material,” Dr. Rhoden continued. “Our study looked at the combined effects of fracture formation and ocean pressurization that occurs as an ocean freezes out. We found that ocean freezing could not generate both the conduits that connect the ice shell with the ocean and the pressure needed to bring ocean material to the near-surface, unless the ice shell was much MUCH thinner than models suggest it could have been. It’s still possible that fractures were created by some other process (or combination of processes) that enabled ocean material to transit the ice shell. But we can’t simply invoke ocean freezing as the direct path to ocean-sourced eruptions.”

As stated, Charon is the largest moon of Pluto, and is nearly half the size of its parent dwarf planet, making it the largest known satellite relative to its parent body, and is even larger than Pluto’s other four moons combined. The only spacecraft to have visited both Pluto and Charon was NASA’s New Horizons in July 2015, which took incredible images and gave us new insights about both celestial bodies. Despite this flyby happening more than seven years ago, scientists continue to learn more about this mysterious moon, to include its ancient ocean and how it could have affected the surface.

The Korea Aerospace Research Institute (KARI) both ended 2022 and started 2023 on a very high note as its first-ever lunar orbiter, Danuri, sent back black-and-white images of the Earth with the Moon’s surface in the foreground that were photographed between December 24 and January 1, KARI announced in a January 3rd statement. Both the images and videos were taken less than 120 kilometers (75 miles) above the Moon’s surface, and will be “used to select potential sites for a Moon landing in 2032,” KARI added in the statement.

As stated, Danuri, also known as the Korea Pathfinder Lunar Orbiter (KPLO), is South Korea’s first-ever lunar orbiter, and was launched on August 4, 2022, onboard a SpaceX Falcon 9 from Cape Canaveral, Florida, and successfully achieved lunar orbit in December 2022. Danuri is slated to begin its scientific mission in February 2023, which has several objectives: analyzing and mapping the lunar surface; measuring gamma rays and magnetic strength; and testing an experimental “space internet” technology by sending images and videos back to Earth, which this most recent image and video cache demonstrated; and identifying potential future landing sites, as noted above.

South Korea’s President Yoon Suk-yeol lauded Danuri’s recent milestones as a “historical moment” in South Korea’s space program.

While Danuri weighs in at 550 kilograms (1212 pounds), the scientific payloads only encompass about 40 kilograms (88 pounds), and consist of several instruments, which include the Lunar Terrain Imager (LUTI), Wide-Angle Polarimetric Camera (PolCam), Magnetometer (KMAG), Gamma-Ray Spectrometer (KGRS), and a NASA-developed high-sensitivity camera (ShadowCam).

ShadowCam is an especially prudent instrument since it will be searching for ice deposits within the Moon’s permanently shadowed regions (PSRs) at the Moon’s poles, and will be beneficial for future exploration, specifically NASA’s Artemis missions which will land astronauts at the lunar south pole later this decade.

The cosmic zoo contains objects so bizarre and extreme that they generate gravitational waves. Scorpius X-1 is part of that strange collection. It’s actually a binary pair: a neutron star orbiting with a low-mass stellar companion called V818 Scorpii. The pair provides a prime target for scientists hunting for so-called “continuous” gravitational waves. Those waves should exist, although none have been detected—yet.

“Scorpius X-1 is one of the most promising sources for detecting these continuous gravitational waves,” said Professor John Whelan from Rochester Institute of Technology’s School of Mathematical Sciences. He’s the principal investigator of RIT’s group in the LIGO Scientific Collaboration, part of a group of scientists focused on the direct detection of gravitational waves. LIGO is the Laser Interferometer Gravitational-Wave Observatory, situated in Washington State and Louisiana. Virgo (in Italy) and KAGRA (in Japan) are also searching for gravitational waves, often in conjunction with LIGO.

Hunting for Gravitational Waves at Scorpius X-1

Whelan’s team used data from the third LIGO-Virgo observing run in their search for continuous gravitational waves from Scorpius X-1. “It’s fairly close at only 9,000 light years away,” said Whelan. “We can see it very brightly in x-rays because the gaseous matter from the companion star is pulled onto the neutron star.”

Despite its brightness, the team did not detect a continuous wash of gravitational waves from Scorpius X-1. That doesn’t mean the waves aren’t there. In fact, their data provide important goalposts as they plan more observations of the pair. It helped them improve their search methodology and should eventually result in the detection of these elusive waves.

“This search yielded the best constraint so far on the possible strength of gravitational waves emitted from Scorpius X-1,” said Jared Wofford, an astrophysical sciences and technology Ph.D. candidate. “For the first time, this search is now sensitive to models of the possible torque balance scenario of the system, which states that the torques of the gravitational wave and accretion of matter onto the neutron star are in balance. In the coming years, we expect better sensitivities from more data taken by Advanced LIGO observing runs probing deeper into the torque balance scenario in hopes to make the first continuous wave detection.”

In a recent study published in Science, a team of researchers at Imperial College London examined 18 meteorites containing the volatile element zinc to help determine their origin, as it has been long hypothesized that Earth’s volatiles materials, including water, were derived from asteroids closer to our home planet. However, their results potentially indicate a much different origin story.

“Our data show that about half of Earth’s zinc inventory was delivered by material from the outer Solar System, beyond the orbit of Jupiter,” Dr. Mark Rehkämper, a professor in the Department of Earth Science and Engineering at Imperial, and a co-author on the study, said in a statement. “Based on current models of early Solar System development, this was completely unexpected.” 

Approximately 4.5 billions years ago, our solar system formed from the collapsed cloud of interstellar gas and dust, whose collapse has been hypothesized to come from the supernova explosion of a nearby star. Upon its collapse, the cloud formed a swirling and spinning disk of material, a solar nebula. Over time, the gravity and pressure at the center of the nebula eventually forced hydrogen and helium atoms to fuse, which birthed our Sun. The remaining material in the nebula formed the planets and moons we see today, with the rocky planets comprising the inner part and the much larger gas planets forming in the outer parts.

Since the Earth formed in this inner part of the nebula, the long-standing hypothesis has been the majority of the Earth-forming materials also came from the inner portion, as well, so this most recent research could help reshape our understanding of both the formation and evolution of our own solar system.

“This contribution of outer Solar System material played a vital role in establishing the Earth’s inventory of volatile chemicals.,” Dr. Rehkämper said in a statement. “It looks as though without the contribution of outer Solar System material, the Earth would have a much lower amount of volatiles than we know it today – making it drier and potentially unable to nourish and sustain life.”

In a recent study submitted to the journal Icarus, a team of researchers at the International Research School of Planetary Science (IRSPS) located at the D’Annunzio University of Chieti-Pescara in Italy conducted a geological analysis of a region on Neptune’s largest moon, Triton, known as Monad Regio to ascertain the geological processes responsible for shaping its surface during its history, and possibly today. These include what are known as endogenic and exogenic processes, which constitute geologic processes occurring internally (endo-) and externally (exo-) on a celestial body. So, what new insights into planetary geologic processes can we learn from this examination of Monad Regio?

“Exogenic geological features, such as glaciers, channels, and coastlines, characterize the bodies of the Solar System that possess, or possessed, a dense atmosphere,” Dr. Davide Sulcanese, who is a Junior Scientist within IRSPS and lead author of the study, recently told Universe Today. “The surface of Earth, Mars and Titan contains a large variety of similar features. Surprisingly, we observed that even in one of the farthest and coldest bodies of the Solar System, the icy satellite Triton, the surface can be reshaped by exogenic processes, including deposition and flowing of ice (though in this case we refer to nitrogen ice).

“Such exogenic activity has already been observed on another body of the outer Solar System, Pluto, where the high-resolution images acquired by the New Horizons spacecraft in 2015 revealed for the first time the presence of active glaciers and dendritic channels on its surface,” Dr. Sulcanese continued. “We showed that also the surface of Triton (at least in Monad Regio) could host several ice flow-related features, like glaciers, moraines, ogives, and subglacial channels, that have probably played a fundamental role in the rejuvenation of its surface.”

For the study, the researchers created a geomorphological map at a scale of 1:1,000,000 of an extended area of Monad Regio, meaning the measurement of 1 on their map is equivalent to 1 million of the same measurement on Monad Regio. They then used a combination of images from NASA’s Voyager 2, a roughness map of the study area, and a digital elevation model to conduct their geological analysis of the area. Their findings indicate that an endogenic phase is potentially followed by an exogenic phase, which could help explain the surface features we see today.

“Most of the morphologies we observed on Triton are a consequence of the internal geological activity of the moon, like diapirism, explosive events, faulting, cryovolcanism and consequent flow of cryolava,” Dr. Sulcanese recently told Universe Today. “However, we infer that after this first endogenic phase, some of these landforms in Monad Regio have been further modified by deposition and flow of solid and liquid nitrogen, forming features strikingly similar to terrestrial glaciers, morains, ogives, channels, and even coastlines.” The study notes that while endogenic processes could be responsible for reshaping the surface early in the moon’s evolutionary history, it is the exogenic processes that could be responsible for actively reshaping its surface today.