At last, GLAST is on-orbit now.
Its solar arrays had deployed and all systems are operating as planned. But it will take 60 days for checkout and calibration before the science operations begin.
GLAST is design to look at gamma rays. It’ll explore the extremely high-energy objects in our universe and hopefully can help us understand some of their mysteries.
Oh, one more thing… GLAST will not be GLAST for long, it’s going to have a new name soon, stay tuned.
Compared to the galaxy cluster below, our Local Group is nothing…
This is the Coma Galaxy Cluster, also known as Abell 1656, located 300 million light-years away. There are thousands of members in this cluster, easily dwarf our Local Group of only 30 over members.
This view of Coma Cluster by Hubble Space Telescope stretches several million light-years across, consists only a portion of the entire cluster, which is more than 20 million light-years in diameter.
Coma Cluster, as it name suggested, lies in the constellation Coma Berenices. This portion of the sky is way out from the plane of the Milky Way, hence it is easier to observe because it is not obscured by the dust and gas in our galaxy.
The cluster is a real collection of galaxies. There is abundance of elliptical galaxies, featureless brownish “fuzzy-balls” which contains old stars staying at the centre. Further out we have spiral galaxies with a distinctive disc structure. Then we have lenticular galaxies, galaxies that are something between an elliptical and a spiral. Lenticulars do show some structure – a bar or a ring perhaps – that may eventually give rise to more disc-like features. And also visible in the image are background galaxies that don’t belong to Coma.
A series of dusty spiral arms appears reddish brown against the whiter disc of the galaxy on the right, suggests that this galaxy has been disturbed at some point in the past, which is not uncommon in galaxy cluster.
Lenticular galaxy in the Coma Cluster with numerous background galaxies.
Source: ESA Space Telescope News Release
Poor GLAST…
After endless of delays, GLAST, which stands for Gamma-ray Large Area Space Telescope, was supposed to launch last week. However, due to an issue with a battery on the launch vehicle, it was again delayed, and re-scheduled to launch today (11-Jun) on a Delta II rocket with a launch window from 11:45 am – 1:40 pm EDT after received the final “Ready to Go!” from all teams.
The launch will be broadcast on NASA TV.
Hopefully this time it will finally blast into space…
<= Delta II rocket that will carry the GLAST spacecraft
Below are some images from the current NASA space shuttle mission, STS-124 at the International Space Station (ISS). The shuttle Discovery was launched on 31 May 2008 for a mission duration of 14 days.
STS-124 shuttle mission is to deliver and install the Pressurized Module and robotic arm of the Japanese Experiment Module, known as “Kibo” (hope), to the International Space Station. This mission is the second of three flights that will launch components to complete the Kibo laboratory. It will also deliver some last minute parts to repair a balky toilet on board the space station.
The Space Shuttle Discovery and its seven-member STS-124 crew head toward Earth-orbit and a scheduled link-up with the International Space Station (ISS).
Backdropped against a blanket of clouds, the STS-124 external fuel tank (ET) begins its relative separation from the Space Shuttle Discovery.
The International Space Station is centered in this image photographed by an STS-124 crewmember as Space Shuttle Discovery approaches the station during rendezvous and docking activities on flight day three. The station just keeps growing in size with every mission.
Astronaut Mike Fossum, STS-124 mission specialist, participates in the mission’s second scheduled session of extravehicular activity (EVA) with astronaut Ron Garan (not in frame).
The Kibo Japanese Pressurized Module and Kibo Japanese logistics module are featured in this image.
It’s carnival time again, this time is held at Out of the Cradle.
This week’s Carnival of Space is dedicated to The Women of Our Space Future.
We will never know for sure how our galaxy looks like from the outside because we are stuck inside.
In the 1950s, astronomers suggested that our galaxy has a spiral structure with four major arms, namely Norma, Scutum-Centaurus, Sagittarius and Perseus Arm. Our Solar System resides near a partial arm called the Orion Arm, between the Sagittarius and Perseus Arm. This early models were built based on radio observations of gas in our galaxy.
In 1990s, astronomers discovered a large bar of stars in the middle of Milky Way through large infrared sky surveys. Infrared light can penetrate through dust, so by using infrared telescopes we can get “clearer” views of our dusty and crowded galactic centre.
In 2005, astronomers discovered that our galaxy’s central bar extends farther out from the centre of our galaxy than previously thought.
And today, astronomers discovered that our Milky Way has only two major arms instead of four, a common structure for galaxies with bars. The result is based on the new infrared imagery from Spitzer of an expansive swath of the Milky Way, stretching 130 degrees across the sky and 1 degree above and below the galaxy’s mid-plane, which includes over 110 million stars,
So, from this:
we revised our model to this:
and now to this:
When astronomer (I mean the software developed by the astronomer) counts the stars in the Spitzer’s images, they found an increase in density of stars in the direction of the Scutum-Centaurus Arm, as expected for a spiral arm. But, when they looked in the direction where they expected to see the Sagittarius and Norma arms, there was no jump in the number of stars. The fourth arm, Perseus, wraps around the outer portion of our galaxy and cannot be seen in the new Spitzer images.
These major arms, the Scutum-Centaurus and Perseus Arms, have the greatest densities of both young, bright stars, and older red-giant stars. The two minor arms, Sagittarius and Norma, are filled with gas and pockets of young stars. Astronomer said the two major arms seem to connect up nicely with the near and far ends of the galaxy’s central bar.
Source: Spitzer Newsroom
Imagine an image 55 metres long… an image about half a football field long…
This is the 55-m mosaic of our galactic plane, broken up into five components, taken by NASA’s Spitzer Space Telescope in infrared. More than 800,000 snapshots have been stitched together to produce this family portrait of stars in our inner galaxy. The image depicts an area of sky 120 degrees wide by 2 degrees tall.
The top strip is the far-left side of the galactic plane; second to top is the area just left of the galactic centre; the middle strip is the galactic centre; second to bottom represents the area to the right of galactic centre; and the bottom one is the far-right side of the plane. These panels represent more than 50 percent of our entire Milky Way Galaxy.
To see and browse the full mosaic, go to GLIMPSE and then launch the GLIMPSE/MIPSGAL Image Viewer.
The swaths of green represent organic molecules, while the heat from warm dust is rendered in red. Star-forming regions appear as swirls of red and yellow, where the warm dust overlaps with the glowing organic molecules. The blue specks sprinkled throughout the photograph are Milky Way stars. The bluish-white haze that hovers heavily in the middle panel is starlight from the older stellar population towards the centre of the galaxy.
When we look up at the night sky, we can see a band of light stretches across the night sky. That band, commonly known as the Milky Way Band, is actually the flat, dusty disk of our galactic plane. Our Earth resides in this disk, roughly 26,000 light years from the centre.
Since the disk is very dusty, we cannot see through the disk with visible light. However, we can use infrared telescopes to see what would otherwise be invisible because infrared light can penetrate the dust. So, with Spitzer’s dust-piercing infrared eyes, astronomers manage to look 60,000 light-years away into this fuzzy band, and saw all the way to the other side of the galaxy.
This is the highest-resolution, largest, most sensitive infrared picture ever taken of our Milky Way. It catalogued more than 100 million stars. This data can help us understand how massive stars form, map the galactic spiral arms and make a better estimate of our galaxy’s star-formation fate.
Source: Spitzer Newsroom
My Dark Sky
My Dark Sky 
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