In the summer of 1989, from a remote expanse of our solar system where sunlight is merely a tepid glow, NASA’s Voyager 2 spacecraft radioed to Earth humankind’s very first images of Neptune. The pictures revealed the sun’s outermost planet was a stunning, deep blue orb. In contrast, Uranus, Neptune’s planetary neighbor and the first to be discovered with a telescope, appeared noticeably paler. Both seemingly twin worlds have a lot in common. They’re roughly the same size, almost equally massive and are both enveloped with deep atmospheres made of…
Read MoreTag: Solar System
Earth’s intense gravity may rip space rocks apart, reducing the risk of ‘planet killer’ asteroids
Every year, dozens of asteroids come closer to our planet than the moon is, and yet catastrophic collisions are exceedingly rare. Now, a new study proposes that Earth has a built-in defense system — its intense gravitational forces — that it uses to tackle asteroid interlopers. The enormous masses of planets and their moons mean they exert tremendous gravitational forces on nearby objects. The differences in gravity these objects experience, called tidal forces because astronomers used them to explain how the moon causes tides on Earth, can be so strong…
Read MorePluto’s ‘almost twin’ dwarf planet Eris is surprisingly squishy
Close to 18 years ago, astronomers spotted a miniature, icy world named Eris billions of miles beyond Neptune. But unlike its dwarf planet cousin Pluto — which New Horizons promoted to a rich, dynamic world after its visit in 2015 — Eris has not had any robotic visitors. It is so far away from Earth, in fact, that it shows up in observations just as a single pixel of light. All in all, scientists know very little about what happens on Eris. Though what we do know is Eris is…
Read MoreEvidence of alien life may exist in the fractures of icy moons around Jupiter and Saturn
Scientists are investigating specific geological features on the largest moons of both Jupiter and Saturn that could be ideal spots for the emergence of life elsewhere in the solar system. The team, led by researchers from the University of Hawaii at Mānoa, looked at what are called “strike-slip faults” on the Jovian moon, Ganymede — the solar system’s largest moon, bigger even than the planet Mercury — and Saturn’s moon, Titan. Faults like these happen when fault walls move past each other horizontally, either to the left or the right,…
Read MoreAstronomers have learned lots about the universe − but how do they study astronomical objects too distant to visit?
This article was originally published at The Conversation. The publication contributed the article to Space.com’s Expert Voices: Op-Ed & Insights. Luke Keller is a Professor of Physics and Astronomy at Ithaca College and has received funding from NASA. NASA’s OSIRIS-REx spacecraft flew by Earth on Sept. 24, 2023, dropping off its sample of dust and pebbles gathered from the surface of near-Earth asteroid Bennu. Analysis of this sample will help scientists understand how the solar system formed and from what sorts of materials. Scientists will begin their analysis in the same facility that analyzed rocks and dust from the…
Read More‘Modest, humble, and uncommonly smart’: How a Soviet mathematician quietly solved the mystery of planet formation
We’ve only got to grips with how the planets in our solar system formed in the last 100 years. In the extract below from “What’s Gotten Into You” (HarperCollins, 2023), Dan Levitt looks at the Soviet mathematician who spent a decade working on a problem that most astronomers had given up on, and — when he finally solved it — was met with disinterest and skepticism. Over 4.8 billion years ago, the atoms that would create us sailed in great clouds of gas and dust, toward… well, nothing. There was…
Read MoreNASA extends New Horizons mission through late 2020s
NASA’s New Horizons spacecraft will be able to keep exploring its exotic environs for at least another five years. The agency announced on Friday (Sept. 29) that it will keep New Horizons‘ lights on while it’s still zooming through the Kuiper Belt, the expansive ring of icy bodies beyond Neptune’s orbit. “The New Horizons mission has a unique position in our solar system to answer important questions about our heliosphere and provide extraordinary opportunities for multidisciplinary science for NASA and the scientific community,” Nicola Fox, associate administrator for NASA’s Science…
Read MoreWhy Are Jupiter’s Rings So Thin?
Why does the biggest planet in the solar system have such flimsy rings? New research shows Jupiter’s moons may be to blame. The post Why Are Jupiter's Rings So Thin? appeared first on Sky & Telescope.
Read MoreWhen Planets Collect Comets
What kind of planets are likely to ensnare comets coming in from the icy outer reaches of a planetary system? The post When Planets Collect Comets appeared first on Sky & Telescope.
Read MoreSee a Rare Transit of Iapetus on July 17–18
It’s tiny. It’s challenging. But you won’t get the chance to see Iapetus transit the globe of Saturn again until 2037! The post See a Rare Transit of Iapetus on July 17–18 appeared first on Sky & Telescope.
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