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Liquid brine can hang around on Mars’ surface, a new study suggests, but conditions may not be great for life as we know it. That’s bad news for any Earth-based microorganisms determined to colonize the Red Planet, but good news for humans who don’t want to contaminate Mars with microbes hitching a ride on robot […] More
Talk about sibling rivalry. Most of the smallest galaxies are “dead,” making no new stars. Now, computer simulations reveal why it is so hard for a tiny galaxy to rejuvenate itself: The galaxy’s existing stars fight the birth of any new ones, even after fresh fuel for star formation falls into the galaxy. These simulations […] More
The closest black hole to the solar system ever spotted may be just 1,000 light-years away. This newfound dark neighbor is at least 4.2 times as massive as the sun, and lives with two ordinary stars whose funny orbits gave the black hole’s presence away, astronomers report May 6 in Astronomy & Astrophysics. Astronomers expect […] More
Comet 2I/Borisov, the solar system’s second known interstellar visitor, probably hails from a planetary family that is chemically distinct from our own. During Borisov’s brief sojourn through the inner solar system, it was enveloped in its own tenuous gas cloud created as the sun baked ice on the comet’s surface (SN: 10/14/19). New observations of […] More
The brightest supernova ever seen may be the first known example of a rare type of stellar explosion. The supernova, spotted in 2016 in a galaxy about 4.6 billion light-years away, radiated about 5 sexdecillion (5 followed by 51 zeros) ergs of energy. That’s about twice the amount of radiation emitted by the previous record-holder, […] More
SpacefarersChristopher WanjekHarvard Univ., $29.95 By 20th century expectations, we are way behind schedule on colonizing the solar system. After the Apollo moon landings, some scientists and NASA officials envisioned launching astronauts to Mars in the 1980s and building cities in space to be habitable by the 2000s. But the only humans in space today are […] More
When giant stars eat giant planets, their starlight may shine a bit less brightly. That dimming could affect how astronomers measure distances across the universe — and possibly even put past measurements in doubt. “You would think the planet would be a small perturbation to the star,” says astrophysicist Licia Verde. “It turns out that […] More
Saturn’s auroras may heat its atmosphere like an electric toaster. Measurements from NASA’s Cassini spacecraft’s final orbits show that Saturn’s upper atmosphere is hottest where its auroras shine, a finding that could help solve a long-standing mystery about the outer planets. Saturn’s upper atmosphere is much hotter than scientists first expected based on the planet’s […] More
