Moon (Dactyl) Discoved Orbiting Asteroid Ida

Dot.Sig writes "Here is a picture and short description of an asteroid with its own moon." Taken by galileo during it's trip to jupiter. Sort of like those pics you take out the car window.... Here is the requisite NASA Press Release. Who names these thing, anyway? Not the first asteroid to be found to have a moon, but interesting regardless.

who names these things?

[larry bagina]

Good question... if you had followed the link, you would know.

The International Astronomical Union (IAU) has approved the name Dactyl for the tiny moon discovered this year in orbit around the asteroid Ida by NASA's Galileo mission.

...

The name is derived from the Dactyli, a group of mythological beings who lived on Mount Ida, where the infant Zeus was hidden -- and raised, in some accounts -- by the nymph Ida and protected by the Dactyli. Other mythological accounts say that the Dactyli were Ida's children by Zeus.

This is news?

[Captain Nitpick]

The picture was taken in 1993.

Ida is first known asteroid with moon...

[heimotikka]

In this page [nasa.gov] it says:

Galileo's two planned visits to the asteroid belt provided the first and second opportunities for close observation of these bodies: in October 1991 the spacecraft flew by asteroid Gaspra, obtaining the world's first close-up asteroid images; in August 1993 it flew by a second asteroid, Ida, and discovered the first confirmed asteroid moon.

I saw this "news" long time ago in a magazine - and it seems that actually this is the first known asteroid with moon. Date in press release you linked is September 20, 1994... It just happened to be chosen as a astronomy picture of the day. Quite old news for the first page?

Re:Ida is first known asteroid with moon...

[heimotikka]

Well - that wasn't on first page (unless you have checked "collapse sections") - human error - seems like we all do mistakes? =) All it takes is little bit checking of facts - if we post some news we should atleast read them first.

Now I've done it - discussing with myself.

Anyone else notice..

[Anonymous Coward]

that the sections on the left are reporting the following today:

science
Jun 31
(1 recent)

Old News

[TheWanderingHermit]

I don't know when the picture was taken (someone here said 1993), but I've had that same picture in use on my desktop as wall paper from time to time since within a year after I switched from Amiga to Wintel (which was about 1996 or 1997) an I've still been using it since I switche to Linux. So I know, from personal experience that pic is at least 5 years old (and I mean literally that pic -- I got it from Views of the Solar System in 1996 when I was researching a project for a teaching seminar) (sorry I don't remember the url for Views of the Solar System, but it's easy to find in Google or Yahoo).

Fixed Link...

[lurp]

http://antwrp.gsfc.nasa.gov/apod/ap020630.html [nasa.gov]

is this a joke or what?

[alonsoac]

I really don't get this, is it supposed to be funny. Just to show how old this "news" are I named my first two computers Dactyl and Ida. Ida was a 486 and is now retired, stored somewhere in my closet. Dactyl is a Amd k6-2 300 mhz which I still have for playing music and games for my brothers. My point is somehow I knew about this a long time ago. What's it doing in the frontpage?

Link has changed

[big_hairy_mama]

The story's link points to a page that changes every day. The real (old, as of midnight) picture is at this page [nasa.gov].

I remember....

[Muad'Dave]

this. They had a contest to name the moon. I thought the most clever name for Ida's moon was Besida ("Beside-uh").

Old news

[shd99004]

I remember reading about this in an astronomy paper i subscribed to back in the 90's...

Awsome Asteroids

[Vought 28]

It is theorized that many asteroids are pure nickel, and hence would be very valuable if we could bring some into a low earth orbit. Also, there is much carbon is space, and carbon forms its familiar diamond lattice only under intense heat and pressure -- such as in planetary collisions. Thus it is believed that many asteroids have a diamond core. (Many asteroids were formed when a planet got hit by something big, either another planet or a huge meteorite) Many skeptics believe scientists say this to procure more funding...not true. Many diamonds on earth are the result of impacts from comets. The heat and pressure of such hits is astronomical, no pun intended.

Binarity in the solar system

[Shooter6947]

Galileo's discovery of Ida in 1993 was quite unexpected and surprising. However, since then we have found that MANY asteroids have companions! Asteroids that pass near to the Earth are the easiest to search, and just today I was told by asteroid expert Rob Whiteley [arizona.edu] that fully 25% of near-Earth asteroids are binary! Craziness.

Recently as well, a binary Kuiper Belt Object [nature.com] was found (in addition to Pluto and Charon, though, I mean). The remarkable ubiquity of double-asteroids and KBOs in our solar system is trying to tell us something about the formation and evolution of planetary systems, and we're working on what that is. I personally suspect that, eventually, a binary extrasolar planet will be found (probably in transit), making this sort of thing even more exciting.