Hubble looks at a six-tailed asteroid. Credit: NASA, ESA, D. Jewitt (University of California, Los Angeles), J. Agarwal (Max Planck Institute for Solar System Research), H. Weaver (Johns Hopkins University Applied Physics Laboratory), M. Mutchler (STScI), and S. Larson (University of Arizona)
How cool is this? It’s an asteroid with an identity crisis. Just like the press release (linked below) says, an asteroid normally appears as a point of light. Not P/2013 P5, this thing is very comet-like in that it has a tail. In fact it has six tails!?
Six Tails? Wait, comets are ice and asteroids are rock. How does that happen?
Careful modeling by team member Jessica Agarwal of the Max Planck Institute for Solar System Research in Lindau, Germany, showed that the tails could have been formed by a series of impulsive dust-ejection events. She calculated that the first ejection event occurred on April 15 and the last one on Sept. 4. The rest sequentially erupted on July 18, July 24, Aug. 8, and Aug. 26. Radiation pressure from the Sun smears out the dust into streamers.
The asteroid could possibly have been spun up if the pressure of sunlight exerted a torque on the body. If the asteroid’s spin rate became fast enough, Jewitt said, the asteroid’s weak gravity would no longer be able to hold it together. Dust might avalanche downslope towards the equator, and maybe shatter and fall off, eventually drifting into space to make a tail. So far, only a small fraction of the main mass, perhaps 100 to 1,000 tons of dust, has been lost. The 700-foot-radius nucleus is thousands of times more massive.
Follow-on observations may show if the dust leaves the asteroid in the equatorial plane, and this would be pretty strong evidence for a rotational breakup. Astronomers will also try to measure the asteroid’s true spin rate.
Here’s the full press release and links to larger images.
Boomerang nebula from ALMA and Hubble. Image credit: NRAO/AUI/NSF/NASA/STScI/JPL-Caltech
An image fitting for Halloween from the Atacama Large Millimeter/submillimeter Array telescope, or ALMA and Hubble of a nebula about 1,533 pc / 5000 light-years away in the constellation Centaurus.
The Boomerang nebula is known as the “coldest place in the universe”. The ghostly shape shown in red is from cold gas molecules as seen from ALMA and the blue background is from Hubble. The Boomerang is known as a pre-planetary nebula, think of the early stages of nebula formation.
And cold? Cold seems to be almost inadequate, the red colored region is just 1 K, that’s one degree Kelvin or -272oC / -458oF. Even the cosmic background radiation is warmer than that.
Check out press release.
I think today is when Europe changes from “Summer Time” so the clocks go back one hour and you get an “hour extra sleep”. Next week it is the US’s turn. Not all locales in either place switch, personally if I’had my way I’d not change either. The thing is, I would not change from Summer Time because I’d like more light at the end of the day.
Also wanted to mention yesterday we had a close visit from a newly discovered asteroid. The asteroid called 2013 UX2 came as close as 0.39 lunar distance or just shy of 150,000 km / 93,000 miles. The asteroid is just now leaving the Earth-Moon system as this post publishes.
2013 UX2 is newly discovered, the designation being assigned to the Catalina Sky Survey. Pretty good catch, this asteroid is only 5-meters in diameter.
More info at the JPL Small Body Database.
WISE spots asteroid 1998 KN3 (bright yellow spot on left) go by near the Orion nebula. Image Credit: NASA/JPL-Caltech
The WISE spacecraft is being reactivated to continue the hunt for asteroids. WISE was launched in December 2009 and was very successful, discovering more than 33,000 new asteroids and comets. One of the many interesting discoveries included the brown dwarf star system just 6.5 light years away.
The primary mission ended in October 2010 when the coolant ran out. A new mission called spacecraft began using two (out of four total) that do not require cryogen for cooling. The NEOWISE mission was scheduled to run a month and ended up being extended three months because it worked so well. After the NEOWISE mission the spacecraft was put into hibernation.
It will be nice to have WISE back in the hunt.
About the image from NASA:
This image shows the potentially hazardous near-Earth object 1998 KN3 as it zips past a cloud of dense gas and dust near the Orion nebula. NEOWISE, the asteroid-hunting portion of the Wide-field Infrared Survey Explorer, or WISE, mission, snapped infrared pictures of the asteroid, seen as the yellow-green dot at upper left. Because asteroids are warmed by the sun to roughly room temperature, they glow brightly at the infrared wavelengths used by WISE.
Denoted with a red arrow, 2013 is the 10,000th NEO found. Click for animated version. Credit: University of Hawaii/NASA
The Pan-STARRS-1 telescope has found the 10,000th Near-Earth Object, it’s name is 2013 MZ5.
From it’s perch on the 10,000 ft (3,000 km) Haleakala crater on Maui.
From the JPL/NASA press release (click for an animation):
“Finding 10,000 near-Earth objects is a significant milestone,” said Lindley Johnson, program executive for NASA’s Near-Earth Object Observations Program at NASA Headquarters, Washington. “But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth.” During Johnson’s decade-long tenure, 76 percent of the NEO discoveries have been made.
Pan-STARRS is Managed by the University of Hawaii, the PanSTARRS survey receives NASA funding.
Among other topics on this episode is the Asteroid challenge, can we find all asteroid threats to Earth. There is also coverage of a memorial to Neil Armstrong.
On the asteroid topic: I get listings of newly discovered and re-discovered asteroids. I like to scan the listings looking at the semi-major axis “a”. We can quickly figure the period of the asteroid in years:
Period = The square root of the cube of the semi-major axis. Simple and quick on almost any calculator, you can even do it in Google. A period of one year means the asteroid has the same orbital period as the Earth, not necessarily the same orbit or anything like that, simple that if it is at let’s say Point X today, a year from now it will be pretty close to Point X again.
There have been some pretty good finds, a couple with orbital periods of better than 80 years. The other day I ran across one with a semi-major axis of 0.849 AU and that is an orbital period of 0.782…years or 285 days. When you see an orbital period of less than one, you know it has a period of less than a year so its orbit is contained inside of that of the Earth.
The asteroid 2010 NG1 does come by and gets kind of close to us on occasion but not terribly so. However a close approach to Venus does seem to be in the offing on 25 Feb 2014. It won’t hit or anything and I’m still trying to sort out how close but you can get an idea by looking at the JPL Orbital Diagram.
NASA and partners have made some improvements on radar imagery of the asteroid 1998 QE2 and its moon. The original image was taken on June 1, 2013 when 1998 QE2 was 3.75 million miles or 6 million km from Earth.
Image credit: NASA/JPL-Caltech/GSSR
Just this morning at 04:42 UTC a smaller asteriod buzzed by Earth at about 65,000 miles / 105,000 km. This asteroid named 2013 LR6 was discovered just hours before on June 6, 2013 by the Catalina Sky Survey. 2013 LR6 30 ft or 10 meter asteroid has an orbital period of about 2.7 years.
More about these on JPL’s Asteroid Watch
If it seems we are hearing more about asteroid flybys, we are, thankfully are looking harder.