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 Ceres is covered in silicates—pyroxenes—that likely came from impacts, the result of infalling material from elsewhere in the asteroid belt…the “dust” of asteroid collisions.
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 many are very dark, move quickly, and could really be anywhere in the sky—it’s a scramble to determine the object’s orbital parameters and figure out just how close it can get to us and when. Such was the case on Oct. 19, 2016, when the asteroid 2016 WJ1 was identified with the Catalina Sky Survey. This object, estimated to be anywhere from 110 to 340 meters across—easily within the potentially hazardous range—was initially calculated to pose a threat in 2065 with a possible impact risk, albeit a very small one. Eventually though, scientists were able to refine the risk chance with more observations of 2016 WJ1…observations that had actually occurred over 13 years earlier.
Read the full story from ESA here: Asteroid sleuths go back to the future
This is an article, now updated, that I originally posted in 2009 during my first year of blogging. Since then more research has been done on the famous 1908 Tunguska Event and we even had a remarkably similar type of thing occur in February 2013 over the Chelyabinsk area, not too far from Tunguska, but even today, the 108th anniversary of the event, scientists aren’t in agreement over what it was that violently exploded over the boggy forests of Siberia—asteroid or comet.
Long the subject of debate, with various theories ranging from meteorite impact to a comet to a flying saucer’s sudden engine meltdown, there’s actually strong evidence that the 1908 “Tunguska Event” was likely caused by the explosion of a comet in the upper atmosphere.
This idea has been suggested before, and is supported by Cornell University engineering professor Michael Kelly’s study of – strangely enough – the space shuttle’s exhaust plumes and their effect on high-atmosphere cloud formation.
To those not familiar with the Tunguska Event, something exploded or impacted in the remote area of Russia on June 30, 1908, flattening the forest in an 830-square-mile area, but leaving no visible crater or other obvious sign of what caused the event. Nearby residents reported the sound of a massive explosion, but that’s about it. Whatever it was, the devastation it caused was extensive and undeniable.
On the afternoon of Oct. 31, 2015, Earth was visited by something much creepier than the typical Halloween trick-or-treater: a dark 2,000-foot (600-meter) -wide asteroid that sped silently (because space) by, approaching at its closest only about 1.3 times the distance to the Moon.
Designated 2015 TB145, this particular near-Earth object had only just been discovered a couple of weeks earlier. And while it posed no danger of impact, its considerable size and high velocity made the close pass a topic of interest for laypeople and scientists alike. By bouncing radar waves off its surface NASA researchers were able to generate an image of 2015 TB145, capturing details that would have been otherwise impossible due to its high velocity and incredibly dark coloration.
Yes, it’s true: a rather not-so-tiny near-Earth
asteroid SKULL-SHAPED ZOMBIE COMET (see below) 2015 TB145 will make a relatively close pass by our dear planet Earth on October 31, aka Halloween — the day when certain beliefs profess that the veil separating the worlds of the living and the dead is at its thinnest, allowing spiritual and even physical interaction to occur between both.
Of course there is no scientific evidence that the latter is at all true but it makes for good scary stories around the light of a campfire. And as the first-world campfires of today are the stark lights of computer monitors and smartphone screens, some are trying to weave scary stories about the passing of this asteroid as well. Should you be afraid? Certainly not. (But there is a cautionary tale to be told.)