What Happens to Solar Systems When Stars Become White Dwarfs?

In this artist's illustration, lumps of debris from a disrupted planetesimal are irregularly spaced on a long and eccentric orbit around a white dwarf. Individual clouds of rubble intermittently pass in front of the white dwarf, blocking some of its light. Because of the various sizes of the fragments in these clumps, the brightness of the white dwarf flickers in a chaotic way. Credit: Dr Mark Garlick/The University of Warwick

In a couple billion years, our Sun will be unrecognizable. It will swell up and become a red giant, then shrink again and become a white dwarf. The inner planets aren’t expected to survive all the mayhem these transitions unleash, but what will happen to them? What will happen to the outer planets?

Continue reading “What Happens to Solar Systems When Stars Become White Dwarfs?”

A 790,000 Year-Old Asteroid Impact Could Explain Seafloor Spherules

A 0.4-millimeter diameter iron-rich spherule. Credit: Avi Loeb/The Galileo Project

Our solar system does not exist in isolation. It formed within a stellar nursery along with hundreds of sibling stars, and even today has the occasional interaction with interstellar objects such as Oumuamua and Borisov. So it’s reasonable to presume that some interstellar material has reached Earth. Recently Avi Loeb and his team earned quite a bit of attention with a study arguing that it had found some of this interstellar stuff on the ocean seabed. But a new study finds that the material has a much more local origin.

Continue reading “A 790,000 Year-Old Asteroid Impact Could Explain Seafloor Spherules”

Water Found on the Surface of an Asteroid

Courtesy of NASA/Carla Thomas/SwRI Using data from NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), Southwest Research Institute scientists have discovered, for the first time, water molecules on the surface of an asteroid. Scientists looked at four silicate-rich asteroids using the FORCAST instrument to isolate the mid-infrared spectral signatures indicative of molecular water on two of them.

Our Solar System is a collection of objects from planets and moons to comets and asteroids. It’s thought there are upwards of 1 million asteroids orbiting the Sun and it was thought that any water present on them should have evaporate long ago. A recent study using data from the SOFIA infrared telescope discovered water on the asteroids Iris and Massalia. 

Continue reading “Water Found on the Surface of an Asteroid”

Webb Directly Images Two Planets Orbiting White Dwarfs

Artist's rendition of a white dwarf from the surface of an orbiting exoplanet. Astronomers have found two giant planet candidates orbiting two white dwarfs. More proof that giant planets can surve their stars' red giant phases. Image Credit: Madden/Cornell University

In several billion years, our Sun will become a white dwarf. What will happen to Jupiter and Saturn when the Sun transitions to become a stellar remnant? Life could go on, though the giant planets will likely drift further away from the Sun.

Continue reading “Webb Directly Images Two Planets Orbiting White Dwarfs”

Some of the Moon's Craters are From Interstellar Impacts. Can We Tell Which?

Far Side of Moon Imaged by MoonKAM. This image of the lunar surface was taken by the MoonKAM system onboard NASA’s Ebb spacecraft on March 15, 2012. Credit: NASA/Caltech-JPL/MIT/SRS

By discovering two interstellar objects (ISOs), we know that asteroids and comets from other star systems pass through the Solar System from time to time. By inference, some of these must have crashed into the Moon, creating impact craters. If we could study the impact sites, we might be able to learn about the star systems that they came from.

A new paper suggests there could be a way to determine which lunar craters came from interstellar object impacts. The authors say that young, small craters with high-melt volume near the Moon’s equator are likely the best candidates for ISO-generated craters on the lunar surface.

Continue reading “Some of the Moon's Craters are From Interstellar Impacts. Can We Tell Which?”

ESA’s Hera Mission is Bringing Two Cubesats Along. They’ll Be Landing on Dimorphos

This illustration shows the ESA's Hera spacecraft and its two CubeSats at the binary asteroid Didymos. Image Credit: ESA

In about one year from now, the European Space Agency will launch its Hera mission. Its destination is the asteroid Didymos, and it’ll be the second human spacecraft to visit the 390-meter chunk of rock. NASA’s DART mission crashed a kinetic impactor into Didymos’ tiny moonlet Dimorphos as a test of planetary defence.

Hera will perform a follow-up investigation of the binary asteroid to measure the size and morphology of the impact crater on Dimorphos. To help it along, it’s taking two tiny CubeSats that will land on Dimorphos.

Continue reading “ESA’s Hera Mission is Bringing Two Cubesats Along. They’ll Be Landing on Dimorphos”

A Huge New Gaia Data Release: More Stars, Gravitational Lenses and Asteroids

The ESA's Gaia observatory expanded its targets to include the tightly-packed center of Omega Centauri, an ancient globular cluster. Image Credit: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO. Acknowedgements: Michele Trabucchi, Nami Mowlavi and Thomas Lebzelter

The ESA’s Gaia mission is releasing a new tranche of astronomical data. The mission has released three regular, massive hauls of data since it launched in 2013, named Gaia DR1, DR2, and DR3. The ESA is calling this one a ‘focused product release,’ and while it’s smaller than the previous three releases, it’s still impactful.

Continue reading “A Huge New Gaia Data Release: More Stars, Gravitational Lenses and Asteroids”

The OSIRIS-REx Capsule Has Landed! Asteroid Samples Returned!

The sample return capsule from NASA’s OSIRIS-REx mission is seen shortly after touching down in the desert, Sunday, Sept. 24, 2023. Credit: NASA

The OSIRIS-REx mission has just completed NASA’s first sample-return mission from a near-Earth asteroid (NEA). The samples arrived at the Utah Test and Training Range (UTTR) near Salt Lake City, where a team of engineers arrived by helicopter to retrieve the sample capsule. The samples will be curated by NASA’s Astromaterials Research and Exploration Science Directorate (ARES) and Japan’s Extraterrestrial Sample Curation Center (ESCuC). Analysis of the rocks and dust obtained from Bennu is expected to provide new insight into the formation and evolution of the Solar System.

Continue reading “The OSIRIS-REx Capsule Has Landed! Asteroid Samples Returned!”

Lucy Has its First Asteroid Target in the Crosshairs

This image shows the tiny main-belt asteroid Dinkinesh. Lucy captured this image from 23 million km away. Image Credit: NASA/Goddard/SwRI/Johns Hopkins APL

NASA’s Lucy spacecraft launched almost one year ago, in October of 2021. Its journey is an ambitious one, and long. It’ll visit eight different asteroids in its planned 12-year mission. Two of them are main belt asteroids, and the other six are Jupiter Trojans, which share the gas giant’s orbit around the Sun.

Lucy’s first, and smallest, target asteroid is now in the spacecraft’s sights.

Continue reading “Lucy Has its First Asteroid Target in the Crosshairs”

DART Had a Surprising Impact on its Target

This Hubble image shows debris from Dimorphos about one day after NASA's DART spacecraft slammed into it. Image Credit: NASA, ESA, STScI, J. Li (PSI)

After NASA’s DART mission slammed into asteroid Dimorphous in September 2022, scientists determined the impact caused tons of rock to be ejected from the small asteroid’s surface. But more importantly, DART’s impact altered Dimorphos’ orbital period, decreasing it by about 33 minutes.

However, a group of researchers measured the orbital period about a month later and discovered that it had increased to 34 minutes — 1 minute longer than the first measurements. Even though it was a single impact from DART, some force continued to slow the asteroid’s orbit, and astronomers don’t yet know what that mechanism might be.

Continue reading “DART Had a Surprising Impact on its Target”