Category: Hubble

Does your cell phone bill ever reach astronomical proportions? Maybe you’re doing too much texting. One space scientist has worked out that sending texts via mobile phones works out to be far more expensive than downloading data from the Hubble Space Telescope. Dr. Nigel Bannister from the University of Leicester looked at the cost of obtaining a megabyte of data from Hubble and compared it with the cost of sending a text. His calculations? “The bottom line is texting is at least 4 times more expensive than transmitting data from Hubble, and is likely to be substantially more than that.”

Bannister says, “The maximum size for a text message is 160 characters, which takes 140 bytes because there are only 7 bits per character in the text messaging system, and we assume the average price for a text message is 5 pence (about .10 USD). There are 1,048,576 bytes in a megabyte, so that’s 1 million/140 = 7490 text messages to transmit one megabyte. At 5p each, that’s £374.49 ($734.25 USD) per MB – or about 4.4 times more expensive than the ‘most pessimistic’ estimate for Hubble Space Telescope transmission costs.”

Dr Bannister said NASA provided the numbers of £8.85 ($17.33 USD) per megabyte for the transmission of data from HST to the Earth.

“This doesn’t include the cost of the ground stations and the time of the personnel along the way, but it is an unambiguous number for that part of the process. So that’s £8.85 to get each MB from Hubble, to the first point of contact on the ground, but no further. Hence we need to go a little bit further to estimate exactly how much it costs to transmit data from Hubble to the end user – i.e. to the data archive which scientists can access. This is difficult, so I had to make some conservative assumptions.”

Dr. Bannister estimated the cost of the data from Hubble could vary between £8.85 and £85 per MB- much cheaper than the £374.49 per MB cost of transmitting one MB of text.

Surprised by the results, Bannister said, “Hubble is by no means a cheap mission – but the mobile phone text costs were pretty astronomical!”

Original News Source: Physorg.com

Astronomers looking at galaxies in the universe’s distant past were surprised to find some compact, very young galaxies that have masses similar to a mature, grown-up galaxy. Using the Hubble Space Telescope, astronomers discovered nine small galaxies, each weighing in at 200 billion times the mass of the Sun. The galaxies, each only 5,000 light-years across, are a fraction of the size of today’s adult galaxies but contain approximately the same number of stars. Each galaxy could fit inside the central hub of our Milky Way Galaxy.

Using the Hubble in conjunction with Keck Observatory in Hawaii, astronomers were able to study the galaxies as they existed 11 billion years ago, when the Universe was less than 3 billion years old.

“Seeing the compact sizes of these galaxies is a puzzle”, said Pieter G. van Dokkum of Yale University in New Haven, Connecticut, USA, who led the study. “No massive galaxy at this distance has ever been observed to be so compact. These galaxies would have to change a lot over 11 billion years, growing five times bigger. They could get larger by colliding with other galaxies, but such collisions may not be the complete answer. It is not yet clear how they would build themselves up to become the large galaxies we see today.”

To determine the sizes of the galaxies, the team used the Near Infrared Camera and Multi-Object Spectrometer on Hubble. For the Keck observations, a powerful laser was used to correct for image blurring caused by the Earth’s atmosphere. Only Hubble, Keck and ESO’s Very Large Telescope are really able to measure the sizes of these galaxies as they are very small and far away.

The ultra-dense galaxies might comprise half of all galaxies of that mass 11 billion years ago, van Dokkum said, forming the building blocks of today’s largest galaxies.

How did these small, crowded galaxies form? One way, suggested van Dokkum, involves the interaction of dark matter and hydrogen gas in the nascent Universe. Dark matter is an invisible form of matter that accounts for most of the Universe’s mass. Shortly after the Big Bang, the Universe contained an uneven landscape of dark matter. Hydrogen gas became trapped in pockets of the invisible material and began spinning rapidly in dark matter’s gravitational whirlpool, forming stars at a furious rate.

Based on the galaxies’ mass, which is derived from their color, the astronomers estimated that the stars are spinning around their galactic disks at roughly 400 to 500 kilometers per second. Stars in today’s galaxies, by contrast, are traveling at about half that speed because they are larger and rotate more slowly than the compact galaxies.

The astronomers say that these galaxies are ideal targets for the Wide Field Camera 3, which is scheduled to be installed aboard Hubble during upcoming Servicing Mission 4 in the fall of 2008.

Original News Source: European Hubble Space Telescope Homepage

59 new images from the Hubble Space Telescope show some very unusual but incredibly spectacular colliding galaxies. Colliding or interacting galaxies are found throughout the Universe, and sometimes these collisions trigger bursts of star formation, or the mergers form new galaxies. The image above shows the aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. Officially called Arp 148, it also has the nickname ‘Mayall’s object.’ It is located in the constellation of Ursa Major, the Great Bear, approximately 500 million light-years away. These images are the largest collection from Hubble ever published simultaneously, and they celebrate the 18th anniversary of Hubble’s launch. And there’s more….


This is a stunning snapshot of a celestial dance performed by a pair of similar sized galaxies. ESO 77-14 is in the constellation of Indus, the Indian, some 550 million light-years away from Earth. The galaxy on the right has a long, bluish arm while its companion has a shorter, redder arm.

The Hubble Site has a video about colliding galaxies.

For the entire collection of these images see the Hubble site.

Original News Source: ESA press release

Although the space shuttles have a busy schedule completing the construction of the International Space Station, there’s one other job to complete – servicing the Hubble Space Telescope. NASA officials announced the details of the mission today at the Winter meeting of the American Astronomical Society. If all goes well, the space shuttle Atlantis will visit Hubble some time around August 2008, carrying 7 astronauts and the spare parts they need to bring Hubble back to top-notch condition.

Over the course of 11 days, the astronauts will perform a total of 5 spacewalks. During these trips to service Hubble, the astronauts will install two new science instruments, upgrade existing instruments and replace failing gyroscopes, batteries and thermal blankets. Atlantis will also reboost the telescope’s decaying orbit.

One of the most critical jobs will be to repair the telescope’s Advanced Camera for Surveys (ACS). This is the visible light instrument that produces the pretty pictures that have made Hubble so famous. The instrument suffered a power failure in January 2007.

With this collection of upgrades, Hubble’s life should be extended to 2013. David Leckrone, Senior Hubble Project Scientist noted that “when the astronauts leave Hubble for the last time, it will be at the apex of its capabilities – better than it has ever been before.” In fact, with these upgrades, Hubble should be 90X more sensitive than before.

One of the unique challenges of this mission will be for the astronauts to repair components that were never designed for orbital repair. In some cases, the astronauts will need to open up boxes and replace circuit boards.

Lead astronaut John Grunsfeld explained just how complex the task of repairing the Advanced Camera for Surveys is going to be, “we’re going to do something that’s never been done before. We’re going to swap circuit boards. We’re going to be working with hundreds of number 4 torque screws. These are really tiny screws. Whatever you do, don’t lose a screw inside the telescope. I have to cut an electromagnetic blanket on the Advanced Cameras for Surveys which could leave sharp edges. We’re astronauts, wearing balloons of air around us, and we don’t like sharp edges. With that removed, I then have to remove 36 of these screws. But they’re at an angle, so I won’t be able to see or reach them easily. I’ve been training in an underwater tank, and plan to get to know each of these screws.”

To demonstrate the tools he’s going to be working with, John Grunsfeld wore his astronaut gloves during his presentation in today’s press conference. “I figured I needed as much practice with these gloves as possible.”

Even the death of Hubble is being arranged. At some point in 2020, when the telescope finally reaches the end of its enhanced lifetime, NASA intends to dock a rocket to the telescope and then drive it into the ocean. As part of this process, the astronauts will install a special docking module, so the deorbiting rocket can attach easily and complete its grim task.