Voyager 2 may have been the second of NASA’s famous twin exploration spacecraft but it launched first, on August 20, 1977. Eight and a half years later it became the first (and last) spacecraft to visit Uranus, at 31,500 miles across the third largest planet in the Solar System. Voyager 2 made its closest pass by Uranus…
Tag: solar system
SOFIA Observations of Ceres Show You Can’t Judge an Asteroid by Its Cover(ing)
The dwarf planet Ceres, at 587 miles wide the largest object in the main asteroid belt between Mars and Jupiter, has a different surface composition than previously thought—and it took NASA and DLR’s Boeing 747-based SOFIA observatory to make the distinction. By observing Ceres in mid-infrared, only possible from high altitudes above infrared-absorbing water vapor, SOFIA found that…
Cassini Has Just Taken the Best Picture of Daphnis Yet!
Hello, Daphnis! On January 16, 2017, the Cassini spacecraft captured the best photo yet of Daphnis, a 5-mile-wide shepherd moon that orbits Saturn inside the Keeler Gap at the outermost edge of the A ring (and also just so happens to be my personal favorite moon of Saturn!) The raw image arrived on Earth today, and…
This is Jupiter Seen from Mars
The HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter (MRO) is specifically designed to take super high-resolution images of the surface of Mars but it also does a pretty darn good job capturing pictures of other objects too—like Jupiter and its Galilean moons, several hundred million miles away! The image above was captured in extended color (i.e. it…
Could This Asteroid Hit Earth? Astronomers Go “Back in Time” to Find the Answer
Astronomers are always watching the skies for observations of near-Earth asteroids—”space rocks” that have orbits close to Earth’s and, in the case of potentially hazardous asteroids (aka PHAs), those whose orbits could actually cross Earth’s and are larger than 150 meters (500 ft) across. When a new one of these is discovered—no small feat considering that…
Asteroid 16 Psyche Could Truly Be a Psychedelic Little World—AND Worth Quadrillions
NASA recently announced the go-ahead for a new Discovery-level mission that would send a spacecraft to explore 16 Psyche, a 130-mile-wide asteroid in the Solar System’s main belt between Mars and Jupiter. 16 Psyche is a relatively small world but is made almost entirely of metals—some of them what we’d consider precious on Earth, like nickel, gold, and…
Light and Dark: the Two Faces of Dione
Saturn’s moon Dione (pronounced DEE-oh-nee) is a heavily-cratered, 700-mile-wide world of ice and rock, its surface slashed by signature “wispy lines” that mark the bright faces of sheer ice cliffs. But Dione has some strange colorations too, evident here in a global map created in 2014 from Cassini images. Its leading half—the side that faces “forward” as…
Eppur Si Muove: Galileo’s Big Night, 407 Years Ago Today
407 years ago tonight, on January 7, 1610, the Pisan astronomer Galileo Galilei looked up at a brilliantly-shining Jupiter through his own handmade telescope and saw three bright little “stars” next to it, stirring his natural scientific curiosity. Further observations over the next several nights showed that the planet wasn’t moving relative to the little “stars” as it…
Bright Clouds Make a Comeback on Titan’s North Pole
Floating high above Titan’s hydrocarbon lakes, wispy clouds have finally started to return to the moon’s northern latitudes…but in much less numbers than expected. Models of Titan’s climate have predicted more cloud activity during early northern summer than what Cassini has observed so far, suggesting that the current understanding of the giant moon’s changing seasons is…
NASA Announces Two New Exploration Missions
Happy New Year! Just four days into 2017 NASA announced its pick for two new Discovery missions to explore our solar system: one to investigate a few of the “Trojan” asteroids that Jupiter has gathered into its orbit with its mighty gravity, and another to visit the remains of an ancient planet’s metallic core! “These are true…
It’s the Beginning of the End for Cassini (But the Pictures Will Be Awesome)
After more than twelve years in orbit around Saturn, NASA’s Cassini spacecraft is now in its final year of operation…and newly-positioned in an orbit that will send it soaring high over the planet’s north pole as well as close by the outer edge of its glorious shining rings. Over the course of 20 week-long “ring-grazing orbits” — the…
More Moons For Uranus?
The distant ice giant Uranus may not have been visited by a spacecraft since Voyager 2’s “Grand Tour” flyby in 1986 but the data gathered then is still being used today to make new discoveries. Most recently, researchers think they have found evidence of two previously unknown moons around Uranus, potentially bringing the planet’s count up…
Lights in the Dark 