Hubble takes an image of Comet Siding Spring and finds two jets coming off the nucleus.
The comet will fly past Mars on October 19 by a distance of only 84,000 miles, which makes understanding its jets crucially important for protecting the various spacecraft that orbit the red planet.
Astronomers have found an asteroid with its own rings.
Chariklo is the largest member of a class known as the Centaurs and it orbits between Saturn and Uranus in the outer Solar System. Predictions had shown that it would pass in front of the star UCAC4 248-108672 on 3 June 2013, as seen from South America. Astronomers using telescopes at seven different locations, including the 1.54-metre Danish and TRAPPIST telescopes at ESO’s La Silla Observatory in Chile, were able to watch the star apparently vanish for a few seconds as its light was blocked by Chariklo — an occultation.
But they found much more than they were expecting. A few seconds before, and again a few seconds after the main occultation there were two further very short dips in the star’s apparent brightness. Something around Chariklo was blocking the light! By comparing what was seen from different sites the team could reconstruct not only the shape and size of the object itself but also the shape, width, orientation and other properties of the newly discovered rings.
The team found that the ring system consists of two sharply confined rings only seven and three kilometres wide, separated by a clear gap of nine kilometres — around a small 250-kilometre diameter object orbiting beyond Saturn.
Astronomers have discovered a new dwarf planet about 300 miles wide at the outer edge of the solar system.
The closest it gets to the Sun is 80 AU, or about 7.4 billion miles. More tantalizing, however,
… the findings also suggest the presence of another large planet in the outer reaches of the solar system. When the authors plotted the motion of Sedna, 2012 VP113, and distant Kuiper belt objects, they noticed some odd behaviors which they couldn’t explain — but which a massive, “super-Earth” planet about 250 AU away could. They note that such a dimly lit planet “would be fainter than current all-sky survey detection limits, as would larger and more distant perturbers” (i.e., planets), so it’s certainly possible… but right now it’s little more than a guess. A weird, intriguing guess.
Using images from the Spitzer Space Telescope, astronomers have assembled a 360 degree zoomable portrait of the plane of the Milky Way galaxy.
The image is in infrared, which is why it can see parts of the galaxy obscured by dust in visible wavelengths, and you can explore it at your leisure, from home.
Using images from Cassini scientists think they have made their first detection of waves on a lake on Titan.
Mercury, the incredible shrinking planet.
An asteroid will eclipse the bright naked eye star Regulus for 14 seconds on March 19-20, and everyone in the New York City metropolitan area will be able to watch.
Late on the night of March 19–20, the faint asteroid Erigone (eh-RIG-uh-nee) will briefly eclipse the bright naked-eye star Regulus for more than 20 million people in the New York metropolitan area and parts of Long Island, New Jersey, Connecticut, upstate New York, and Ontario. The star will vanish from sight for up to 14 seconds around 2:06 a.m. EDT on the morning of the 20th for New Yorkers, and a minute or two later farther north.
If the sky is clear, Regulus will be a cinch for anyone to spot — no astronomy experience required! Around 2 a.m. or a bit before, go out and face the Moon. Extend your arms straight out to your sides. Regulus will be straight above your right hand, roughly as high as the Moon is. It’s the brightest star in that area.
Scientists are also asking ordinary citizens to help gather data, which if sufficient will allow them to recreate a reasonably accurate silhouette of the asteroid, thus determining its size and shape.
Astronomers have found the largest yellow star yet, 1,300 times bigger than the Sun.
My heart bleeds: The IAU has issued a press release condemning the public’s naming of Martian craters as initiated by the private company Uwingu.
This war over the right to name features on other planets is mostly a tempest in a teapot, as the actual names will finally be decided by the people who end up living there. Nonetheless, I really like how Uwingu is pushing the IAU’s buttons, as that organization’s self-righteous insistence that it has the power to name everything in space, from craters to the smallest boulders, has for years struck me as pompous and wrong.
The Milky Way’s council of galaxies.
“All bright galaxies within 20 million light years, including us, are organized in a ‘Local Sheet’ 34-million light years across and only 1.5-million light years thick,” says McCall. “The Milky Way and Andromeda are encircled by twelve large galaxies arranged in a ring about 24-million light years across – this ‘Council of Giants’ stands in gravitational judgment of the Local Group by restricting its range of influence.”
McCall says twelve of the fourteen giants in the Local Sheet, including the Milky Way and Andromeda, are “spiral galaxies” which have highly flattened disks in which stars are forming. The remaining two are more puffy “elliptical galaxies”, whose stellar bulks were laid down long ago. Intriguingly, the two ellipticals sit on opposite sides of the Council. Winds expelled in the earliest phases of their development might have shepherded gas towards the Local Group, thereby helping to build the disks of the Milky Way and Andromeda.
WISE’s survey of the sky in infrared has now shown that there is no large planet X orbiting beyond Pluto.
This recent study, which involved an examination of WISE data covering the entire sky in infrared light, found no object the size of Saturn or larger exists out to a distance of 10,000 astronomical units (au), and no object larger than Jupiter exists out to 26,000 au. One astronomical unit equals 93 million miles. Earth is 1 au, and Pluto about 40 au, from the sun. “The outer solar system probably does not contain a large gas giant planet, or a small, companion star,” said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.
The theory, popular among planetary scientists and journalists, is that this theorized distant planet would periodically disturb the orbits of comets in the Oort Cloud, sending them raining down on Earth and thus cause the periodic extinction events found in the paleontological record. It was a cute theory, but based on little data. Now we have the data, and no such planet exists.
The data has found a lot of previously unknown nearby stars and brown dwarfs, which is significant in that they are close and can be studied more easily.
Chicken Little report: Another rock will fly past the Earth today, killing no one.
The 33-foot-wide (10 meters) near-Earth asteroid 2014 EC will come within 34,550 miles (55,600 kilometers) of Earth’s surface this evening (March 6) — just 14 percent of the distance between our planet and the moon, which is about 239,000 miles (385,000 km) on average.
The key quote, however, is this:
Such back-to-back flybys are pretty special, though they can’t exactly be called rare events, [JPL scientist Don] Yeomans said. “For small asteroids, one would expect a flyby of the Earth, to within the moon’s distance, about every two weeks,” he said.
In other words, these flybys happen a lot, with no consequences.
