Pluto is bigger than Eris

A rare occultation of a star by the Kuiper Belt Object known as Eris was recorded in several stations in Chile and at first glance the data suggest Eris is in fact smaller than Pluto--the albedo of Eris must be higher than predicted.

Sky & Telescope has a good write-up.

Here's a report from one of the observers.

And here's Mike Brown's take on the observation (An observation of the observation).

Another impact on Jupiter

http://www.skyandtelescope.com/observing/home/101264994.html

My first thought once it was confirmed was "What is the real rate of visible Jovian impacts versus our sampling rate of looking for them?".

Saturn visible behind Lutetia during flyby

Hey, this is pretty cool; I'm always a fan of planetary conjunctions.

Saturn was visible in a few of the images of Lutetia taken by Rosetta as it passed by!

Fly-by of Lutetia is a success

Another successful asteroid fly-by!
http://www.planetary.org/blog/article/00002577/

Hayabusa coming home

An amazing comeback for the little falcon that could--


Credit: ISAS / JAXA / Øyvind Guldbrandsen / Planetary Society Blog

The Japanese spacecraft Hayabusa will be returning to Earth with perhaps a sample of the asteroid Itokawa in just four days. This spacecraft has had as many setbacks in the seven years it's been running as you can have without losing the craft completely. When they released the data archive in 2007 I made a color image of Earth made by Hayabusa during a flyby and some more surface close-ups here.

Visible Jovian impact

Link and run: http://arstechnica.com/science/news/2010/06/breaking-news-jupiter-hit-by-yet-another-impactor.ars

An asteroid collision

Color me surprised: I did not believe, when this object was first reported, and further debate on the Minor Planet Mailing List, that this was in fact a collision.

2010 AL30 animation

Patrick Wiggins makes a cool animation of an object passing by the Earth last week:
http://users.wirelessbeehive.com/~paw/temp/2010AL30.2.GIF

I liked it better than some of the other animations I've seen of the same object, since he didn't center the object on every frame but let it move to the right. This gives the effect of it speeding up.

Two awesome things you have already heard about

The LRO imaged most of the Apollo landing site on the Moon. Things will get better as the orbital parameters are modified.

There appears to have been an impact of some sort on Jupiter, first seen by an Australian amateur.

Inbound bolide: 2008 TC3

Astronomers have discovered a small inbound object a few meters across that appears to be on an impact course with the Earth. The object may enter the Earth's atmosphere somewhere over Europe or North Africa just after 2:30AM UT Tuesday (9:30PM CDT tonight). The orbit is uncertain enough to have a number of possible interactions with the Earth, including missing entirely. It is small enough, based on its brightness, to cause no concern, but should be a nice bright fireball and might drop some meteorites. The self-assigned ID is 8TA9D69, and it was discovered on Mt. Lemmon near Tucson, Arizona by the Mt. Lemmon Sky Survey.
http://tech.groups.yahoo.com/group/mpml/message/21070

Update: It's now designated 2008 TC3
http://cfa-www.harvard.edu/mpec/K08/K08T50.html

Latest Mars Asteroid update

The latest observations nearly exclude the possibility of 2007 WD5 colliding with Mars, dropping the probability to 0.01%.

http://neo.jpl.nasa.gov/news/news156.html

This unfolding story and the present results have been made possible by the tracking efforts of many astronomers at several observatories around the world:

* 2007 WD5 was discovered using the Mt. Lemmon 1.5-meter telescope by Andrea Boattini of the University of Arizona's Catalina Sky Survey, which is led by Steve Larson.
* Follow-up from archival images taken by the 1.8-meter telescope on Kitt Peak in Arizona were provided by Terrence H. Brezzi of the University of Arizona's Spacewatch Project, which is led by Robert McMillan.
* Andy Puckett of the Univ. of Alaska obtained pre-discovery measurements from archival images of the Sloan Digital Sky Survey’s 2.5-meter telescope on Apache Point, NM.
* Bill Ryan of New Mexico Tech's Magdalena Ridge Observatory observed 2007 WD5 on several crucial nights, with critical support from university and observatory staff.
* Observations from the 6.5-meter Multi-Mirror Telescope (MMT) Observatory in Arizona were provided by a team consisting of Holger Israel (Univ. Bonn), Matt Holman (Harvard/CfA), Steve Larson (Univ. Ariz.), Faith Vilas (MMTO), Cesar Fuentes (Harvard/CfA), David Trilling (Univ. Ariz.) and Maureen Conroy (Harvard/CfA).
* The 3.5-meter telescope at the Calar Alto Observatory in Spain provided follow-up through a team consisting of Adriano Campo Bagatin (Univ. Alicante), Gilles Bergond (Calar Alto Obs.), Rene Duffard (Inst. de Astrofisica de Andalucia), Jose Luis Ortiz (Inst. de Astrofisica de Andalucia), Reiner Stoss (Obs. Astronomico de Mallorca and Astronomisches Rechen-Institut) and Javier Licandro (Inst. de Astrofisica de Canarias).
* Fabrizio Bernardi, Marco Micheli and Dave Tholen of the Univ. of Hawaii Institute for Astronomy observed the asteroid at its faintest using the 2.2-meter UH telescope on Mauna Kea in Hawaii.

End of the year non-review #2: More Hayabusa data

I played with the first of the Hayabusa data a few days ago (by that I mean in July)--and Emily Lakdawalla at the Planetary Society is too--see their post and the great rotation animation. I've been playing with a single image of the surface. If you just add the colors together, you get a relatively neutral surface:

A relatively colorless image

If you boost the saturation of the image you can begin to see significant differences in the rocks on the surface and the underlying regolith.

(movement of the satellite is the source of the color fringes)

Near-infrared Spectral Results of Asteroid Itokawa..." talks about the rich pyroxene and olivine (olivine being a very simple Fe and Mg silicate) results--suggesting the origin of the asteroid was from the inner asteroid belt, with any variations in spectra due to clast size. (see this graph for an example) (both links may require a subscription).

P.S. See additional Itokawa talk here. And see my synthesis of a color image of Earth from Hayabusa.

P.P.S. Look at that crazy huge boulder sitting on the surface: here and here!

Update on the Mars asteroid

New observations reduce the possibility from 1/75 (1.33%) to 0.3%. (via the MPML). The error ellipse has moved from near the center of a large uncertainity to the edge of the ellipse. See a diagram here.

The Mars asteroid thingy

http://www.space.com/scienceastronomy/071220-asteroid-mars.html

Speaking of 2007 WD5, the orbit is weakly constrained because the observations extend to only 29 days. The object was discovered on November 20th after it passed Earth some 4.5 million miles away on November 2th. It's currently only magnitude 22 and fading, and the moon is getting brighter in the same part of the sky, so there will be no observations for at least a week. In fact, the moon will be two moon diameters away from 2007 WD5 on Saturday evening, if you'd like an idea of where the minor planet is now in the sky. Mars is unmistakable at opposition in the East in the constellation Gemini in the evening. At time of possible impact, Mars will be in the horns of Taurus.

Usually these sorts of things tend to clear up after just a few more observations constrain the orbit better. Since it's so faint, a number of the observatories doing this sort of work (and a lot of them are amateurs doing it for free) won't be able to see it.

http://neo.jpl.nasa.gov/news/news151.html
A good press release, with the error ellipse, which you can see is very, very long.


Play with this java orbit visualizer: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007%20WD5&orb=1

My old-fashioned planetarium program has a miss by quite a distance, but I wouldn't really be shocked at that.

Anyways, go out and see the Moon and Mars close together on Sunday night. It'll be beautiful. In the right place on Earth, the Moon will occult it.

P.S. This wouldn't be the first impact seen on Mars. The Mars Global Surveyor found 20 new craters over the course of it's mission.

Incoming asteroid--errr, satellite

Astronomers at the Catalina Sky Survey near Tucson discovered an object on November 7th and when the orbit was calculated it was a Near Earth Object (or NEO) and would barely pass by Earth in only five days time. By barely, it was calculated at only a Earth's diameter away--a little under 8,000 miles.

Photometric measurements suggested the object was 20m in diameter, which is pretty big as things go--the Meteor Crater parent body was estimated at 30-50m.

But as Russian astronomer Denis Denisenko noted on the MPML, the object had a peculiar orbit: it passed quite close by Mars at nearly the same time as an ESA orbiter called Rosetta. See a view at Mars here. And, Rosetta happens to have the largest solar panels short of the ISS, two 14 meter long panels that make 64 square meters in total, matching the expected brightness of the object. Sure enough, Rosetta is due at Earth for a orbit changing interaction with Earth in five days so it can rendezvous with a comet in 2014. The people in charge of maintaining minor planet orbits decried the lack of coordination between the artificial satellite organizations and the minor planet community--as satellites are launched it's easy to watch them go away, but the NEO watchers are rightfully concerned about inbound objects, and the data about spacecraft outside of near-Earth space is skimpy.

Hayabusa data release

The ambitious Japanese asteroid project, Hayabusa, has released its data archive. The asteroid Itokawa was the target; whether they successfully picked up any of it might be known if the spacecraft returns to Earth successfully in 2010.

The imager on the spacecraft was AMICA, and the data archive is available here. A sample image would be this one, showing Itokawa truly is a rubble pile.

I took three filtered images taken during an Earth flyby and made the image above from them. I'll play with some of the Itowaka images as well and see what comes out of them.

Space Debris vs. Jet Plane: Debunked

Surely you've read the news story about a Chilean jet narrowly missing space debris near New Zealand. I can safely say, as the story is written, it didn't happen.

Meteors are notoriously described with outrageously close distances-- "extinguished below the horizon", "no more than 3 - 5 thousand feet high when directly above me", etc., despite the luminous portion of the meteor flight starting at 120-75km altitude, and ending by 20km altitude. How did the pilot see this object, if it was no longer luminous, at his flight elevation? Let alone "knowing" it was only five miles away from the plane. Likely, he had received notice that the Russians were deorbiting a satellite that day, albeit twelve hours later, and saw the meteor and mistakenly claims near-disaster.

Pilots have long mistaken meteors as being close--the grandfather of meteoritics,
Harvey H. Nininger, called their reports "humorous at best". In fact, you should read that entire article: http://www.meteoritearticles.com/mitterling17.html.

During Nininger's time a number of airpilots reported having to take evasive steps to prevent collisions with falling meteors. One such newspaper reported an startling account of how a resourceful pilot battled a shower of meteors by making a serious of dips and swerves to avoid the incoming falling meteors saving himself, his eleven passengers, as well as the aircraft. One other pilot was said to have dipped his right wing to avoid a similar collision of a meteor which happened in Nebraska. Yet another pilot near Cheyenne Wyoming said he narrowly escaped injury when en-countering one of those pestiferous fiery projectiles which threaten to side swipe him from the left. He "ducked", however and the missile sailed by, leaving him unharmed.
...
Nininger knew of the fall of those cited above and concluded that the second pilot who thought he saw the meteor below him, plotted the meteor height at the burnout point at about 17 miles high, above the northeastern New Mexico soil. The second pilot who saw the same meteor fall was slightly more than a hundred miles from it at its nearest approach. The pilot over Nebraska that dipped his wing to avoid collision was 68 miles south of the line over which the dreaded missile was speeding at an elevation of approximately 20 miles.

Pilots in the 1920's were having difficulty giving range to bright objects--what makes anyone think they still aren't?