The Antennae Galaxies are about 20 million light-years closer than was thought. That’s the result of new research from an international group led by Ivo Savianne from the European Southern Observatory using the Hubble Space Telescope and ground based observations.

The research put the distance estimate at 45 million light-years, the former estimate was 65 million light-years. You might be tempted to thinking how can that possibly be, after all that is a big difference and how can that possibly be. Cosmic distances may seem to be pretty routine; in reality it’s not like getting out a ruler and it turns out that determining distances is one of the most difficult things in professional astronomy.

The Antennae Galaxies are the closest pair of colliding galaxies, and at a magnitude 10.9 are easily visible with a modest telescope. The coordinates are RA: 12h 01m 52.8s / Dec: -18°51′54” (Epoch 2000).

The press release is very good and there are other images (and larger formats) there too, check it out. BTW, I noted Robert Gendler is in the credits and he is one of the world’s best astrophotographers; I’ve enjoyed his work for years.

Credit: NASA, ESA & Ivo Saviane (European Southern Observatory)/Robert Gendler

Atlas is winning.

I have to get my pencil out and see if I can calculate these orbital speeds, interesting how much faster Atlas is moving than Prometheus.

The Cassini press release:
Two of Saturn’s ring moons draw close momentarily, before the inner of the pair moves off alone.

Atlas (30 kilometers, or 19 miles across, at center right) passes Prometheus (86 kilometers, or 53 miles across, at center left) about once a month, then slowly and steadily pulls ahead of its slower moving sibling.

This view looks toward the unilluminated side of the rings from about 23 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 6, 2008. The view was acquired at a distance of approximately 1.6 million kilometers (975,000 miles) from Atlas. Image scale is 9 kilometers (6 miles) per pixel.

Credit: NASA/JPL/Space Science Institute

NASA is getting ready to launch a planet hunter, this is especially good because this is another one of the missions you can add your name to.

The Kepler mission is extremely ambitious:
The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. This is achieved by surveying a large sample of stars to:

1. Determine the percentage of terrestrial and larger planets there are in or near the habitable zone of a wide variety of stars;
2. Determine the distribution of sizes and shapes of the orbits of these planets;
3. Estimate how many planets there are in multiple-star systems;
4. Determine the variety of orbit sizes and planet reflectivities, sizes, masses and densities of short-period giant planets;
5. Identify additional members of each discovered planetary system using other techniques; and
6. Determine the properties of those stars that harbor planetary systems.

And more!

As for getting your name on the mission, the names collected will be put on a DVD and mounted on the spacecraft later this year, they are even going to video the event.

You can get your name including and if you want you can include a description of why you think the Kepler mission and the hunt for extra solar Earthlike planets is important. All you have to do is go to the Kepler website, which includes a few interesting projects (a planisphere!) and a link to a great interactive webpage.

Click here to go to the Kepler page. The Name in Space program is being done in association with the International Year of Astronomy 2009 and the 400^th anniversary of the Kepler’s publication of the first two of his famous laws.

Image: Jon Lomberg

The European Space Agency (ESA) has an x-ray observatory called XMM-Newton and a team of international astronomers to find part of the “missing” matter in the universe.

A number of years ago scientists predicted that half of the missing “normal” matter was simply made of atoms existing in low density gas between galaxies. No they mean really low density gas, density so low it is hard to detect. What they did was detect the warmest part of this interstitial space.

That’s “normal matter” and amazingly that is only about 5 percent of what makes up the universe. Pretty hard to imagine isn’t it? 95 percent of the universe is made up of stuff we can’t see, touch, or detect. It’s a combination of “dark matter (23%) and dark energy (72%). Strange stuff! Astroprof has done a few great posts on dark matter, here’s a like to the first one.

To read more about the discovery, which is a pretty significant find go here.

About the image (Credit: ESA/ XMM-Newton/ EPIC/ ESO (J. Dietrich)/ SRON (N. Werner)/ MPE (A. Finoguenov)):
Composite optical and X-ray image of galaxy clusters Abell 222 and Abell 223. The cluster pair is connected by a filament permeated by hot X-ray emitting gas.

The optical image was obtained by SuprimeCam at the Subaru telescope, the X-ray image showing the distribution of the diffuse hot gas (yellow to red) was obtained by XMM-Newton.

Incidentally the bright vertical lines on some of the stars is due to the pixel on the CCD chip becoming saturated, very common even if you don’t see it a lot in published images — it’s called blooming.

McDonald Observatory astronomers have found a new kind of star. The star is a “pulsating carbon white dwarf” a new class of white dwarf. This is the first new type of variable white dwarf found in 25 years.

White dwarfs are interesting for a number of reasons, not the least of which is, our Sun will end up as a white dwarf. Usually at this point in their lives, white dwarfs have an outer shell of hydrogen or helium; this star has a carbon shell (in a gas form of course), and this one pulsates its brightness two percent about every eight minutes.

The star is only 800 light-years away in Ursa Major, also known as the Big Dipper, and has not-so-memorable name: SDSS J142625.71+575218.3.

I was all cranked up to take a look just for fun to see if I could see this star, had clear skies for once and all day, up until about an hour ago. Darn it. Oh well, gotta take the sweet with the sour as they say.

Head over to the McDonald Observatory to find much more detail about the star.

Image: Sloan Digital Sky Survey Collaboration / McDonald Observatory

On Friday (May 2) the Shuttle Discovery was rolled out of the Vehicle Assembly Building just before lunch time.  By the time the shuttle was firmly attached to the pad it was just after 6 am on Saturday morning.

When Discovery launches on May 31^st, it will be known as STS-124 and will be commanded by Mark Kelly.  In the meantime the astronaut crew will be arriving on Tuesday May 6, to take part in three days of dress rehearsals for the countdown.

The main payloads for the mission, Japan’s, Kibo Pressurized Module and Remote Manipulator System arrived a few days ago and you would think it would have been loaded into the payload bay before roll out, but no, payload can be loaded right at the pad.  The Kibo module consists of six components and will be finished by STS-127. More about that later. . . .

Here’s NASA’s Kibo page.
Here’s JAXA’S Kibo page.

As I was writing this I was thinking Discovery sure has made a lot of flights, in fact, this will be the 35^th flight for the shuttle.

Image credit: NASA/Troy Cryder