Whether you think Pluto is a planet, a dwarf planet, a Kuiper Belt Object – or something else entirely – you should still be fascinated by this: a video of the dwarf planet Pluto and its largest moon Charon showing the two distinctly separate worlds actually in motion around each other! Captured by the New Horizons spacecraft from July 19–24, the 12 images that comprise this animation were acquired with the Long Range Reconnaissance Imager (LORRI) instrument from distances of 267 million to 262 million miles (429 million to 422 million km) and show nearly a full orbital rotation. Amazing!
Wrapped in an atmosphere tinted pale blue by high-altitude methane, Uranus has occasionally been observed to develop large storms in its frigid windy skies. NASA’s Voyager 2 saw a few small storm clouds spotting Uranus during its flyby in Jan. 1986, and more recently some large but short-lived storms were observed by Hubble and the W.M. Keck Observatory as the planet moved toward its equinox in 2007. Now, seven years after its equinox, swirling storms are once again blooming on Uranus — and Keck astronomers have caught them on camera (while preparing for terrestrial hurricanes to make landfall!)
Having made over 3,000 orbits of Venus over the past eight years, ESA’s Venus Express has (as of May 15) completed its science mission and is now in the final few months of its operational life. With a nothing-left-to-lose attitude, the spacecraft recently made a daring and risky dive down into the upper layers of the planet’s thick atmosphere, coming within 80 miles of Venus’ broiling surface on July 12 — that’s the closest any human-made spacecraft have gotten to Venus since the Soviet Vega balloon-and-lander missions of 1985!
As dangerous as it may have been for the spacecraft, Venus Express survived the encounter and grabbed some valuable data about the planet’s atmosphere along the way. It’s now working its way up to a higher altitude orbit, but there’s no escaping the fact that its fuel reserves are nearly depleted and it will soon be back on its way down into Venus’ atmosphere on a mission-ending, one-way trip.
Just a week after Curiosity celebrated its first Martian year in Gale Crater and we have yet another milestone anniversary in Solar System exploration: as of 10:48 p.m. EDT tonight Cassini will have been in orbit around Saturn for a full decade!
“There are times when human language is inadequate, when emotions choke the mind, when the magnitude of events cannot properly be conveyed by the same syllables we use to navigate everyday life. The evening of June 30, 2004 was such a time.”
– Carolyn Porco, Cassini Imaging Team Leader, CICLOPS “Captain’s Log” on June 30, 2014
That’s ten years and over 2 billion miles of discoveries and explorations of our Solar System’s most majestic planet and its incredibly varied family of moons. Over the course of its primary mission and three extended missions, we have been able to get a close-up look at Saturn and its moons like never before, witnessing first-hand the changes that occur as their seasons change. What’s been discovered by the Cassini mission about Saturn has offered invaluable insight into the evolution of our entire Solar System, as well as planets that could be found elsewhere in our galaxy.
“Having a healthy, long-lived spacecraft at Saturn has afforded us a precious opportunity,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By having a decade there with Cassini, we have been privileged to witness never-before-seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life.”
Launched on October 15, 1997, the Cassini-Huygens spacecraft established orbit around Saturn on June 30, 2004 (July 1, UTC).
NASA’s Curiosity rover may be busy exploring the rugged and rocky interior of Gale Crater but it does get a chance to skygaze on occasion. And while looking at the Sun on June 3, 2014 (mission Sol 649) the rover’s Mastcam spotted another member of our Solar System: tiny Mercury, flitting across the Sun’s face.
Silhouetted against the bright disk of the Sun, Mercury barely appears as a hazy blur in the filtered Mastcam image above. But it was moving relatively quickly during the transit and passed the darker smudges of two Earth-sized sunspots over the course of several hours. It was the first time Mercury has ever been imaged from Mars, and also the first time we’ve observed a planet transiting our Sun from another world besides our own.
Read the rest of my article (and watch a cool animation of the transit) on Universe Today here.
Image credit: NASA/JPL-Caltech/MSSS/Texas A&M
It used to be said with confidence by even grade-school kids that the largest storm in the Solar System was Jupiter’s Great Red Spot, which has been churning for at least 350 years and could fit three Earths across it. And while it’s true that the GRS is a truly enormous hurricane by Earthly standards, these days it’s not as “great” as it used to be — over the past couple of decades the GRS has shrunk to only about a third of its former size.
“Recent Hubble Space Telescope observations confirm that the Great Red Spot (GRS) is now approximately 10,250 miles across, the smallest diameter we’ve ever measured,” said Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
That equals about 16,500 kilometers, or about one and one-third Earths across. Which is still very big, yes, but nothing compared to what it once was!
Mercury’s ready for its close-up, Mr. MESSENGER! At an incredible 5 meters per pixel, the image above is one of the highest-resolution images of Mercury’s surface ever captured. It was acquired on March 15 with the MESSENGER spacecraft’s MDIS (Mercury Dual Imaging System) instrument and shows an 8.3-km (5.2-mile) -wide section of the planet’s north polar region, speckled with small craters and softly rolling hills.
And, with a new low-altitude mission ahead, there’ll be plenty more like this — and likely even better — in the months ahead. Read the rest of this article here.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington