Young Stars in an Old Galaxy

Image credit: Hubble

Astronomers have spotted a number of young stellar clusters dotted around a very old elliptical galaxy – this disputes the established theory that old galaxies contain only older stars. The team used the Hubble Space Telescope and the ESO Very Large Telescope to take a series of images of galaxy NGC 4365, and they were able to identify star clusters that were only a few billion years old, while the majority were over 12 billion years old. Why the galaxy contains such a combination of young and old stars is still a mystery.

Combining data from the NASA/ESA Hubble Space Telescope and the ESO Very Large Telescope (VLT), a group of European and American astronomers have made a major discovery. They have identified a huge number of ‘young’ stellar clusters, in an old elliptical galaxy.

For the first time, it has been possible to identify several distinct periods of star formation in a galaxy as old as this one. Elliptical galaxies have always been considered to have undergone one early star-forming period and thereafter to be devoid of star formation. However, the combination of the best and largest telescopes in space and on the ground has now clearly shown that there is more than meets the eye.

Do elliptical galaxies only contain old stars?
One of the challenges of modern astronomy is to understand how galaxies – large systems of stars, gas and dust – form and evolve. When did most of the stars in the Universe form? Did this happen at a very early stage, within a few billion years of the Big Bang? Have a significant number of the stars we now observe formed much more recently?

Spectacular collisions between galaxies take place all the time, triggering the formation of thousands or even millions of stars. However, when looking at the Universe as a whole, most of its stars are found in elliptical galaxies whose overall appearance has so far led us to believe that they, and their stars and as well, are old.

These elliptical galaxies do shine with the diffuse, reddish glow normally associated with stars that are many thousand million years old. However, what is the underlying mix of stars that produces this elderly appearance? Could a significant number of much younger stars be ‘hiding’ among the older ones?

Detailed observations with the world’s premier telescopes have now cast new light on this central question about the behaviour of some of the major building blocks of the Universe.

Cosmic paleonthology
To break the stellar ‘cocktail’ in elliptical galaxies down into its different constituents, a team of European and American astronomers observed massive stellar clusters in and around nearby galaxies. These “globular” clusters, so called because of their shape, exist in large numbers around all observed galaxies and form a kind of ‘skeleton’ within their host galaxies. These ‘bones’ receive an imprint for every episode of star formation they undergo. By reading the ages of the globular clusters in a galaxy, it is possible to identify the past epoch(s) of active star formation in a galaxy.

Reading the imprints and deducing the distribution of ages of the globular clusters, astronomers can reveal when many of the stars in elliptical galaxies formed. This is similar to the way a palaeontologist uses the skeletons of dinosaurs to deduce information about the era in which they lived.

A surprising discovery
The team combined images of a number of galaxies from Hubble’s Wide Field and Planetary Camera 2 with infrared images obtained from the multi-mode ISAAC instrument on the 8.2m VLT Antu telescope at the ESO Paranal Observatory (Chile). To their great surprise, they discovered that many of the globular clusters in one of these galaxies, NGC 4365, a member of the large Virgo cluster of galaxies, were only a few thousand million years old, much younger than most of the other stars in this galaxy (roughly 12 thousand million years old).

The astronomers were able to identify three major groups of stellar clusters. There is an old population of clusters of metal-poor stars, some clusters of old but metal-rich stars and now, seen for the first time, a population of clusters with young and metal-rich stars.

These results have been fully confirmed by spectroscopic observations made with another of the world’s giant telescopes, the 10-metre Keck on Hawaii.

“It is a great pleasure to see two projects wholly or partly funded by Europe – VLT and Hubble – work in concert to produce such an important scientific result”, says Piero Benvenuti, ESA Hubble Project Scientist. “The synergy between the most advanced ground and space telescopes continues to prove its effectiveness, paving the way to impressive new discoveries that would not otherwise be possible.”

The discovery of young globular clusters within old galaxies is surprising since the stars in the giant elliptical galaxies were until now believed to have formed during a single period early in the history of the Universe. It is now clear that some of the galaxies may be hiding their true nature and have indeed experienced much more recent periods of major star formation.

Original Source: ESA News Release

Progress Cargo Ship Launches

Image credit: NASA

A Progress supply ship lifted off from the Baikonur Cosmodrome in Kazakhstan on Wednesday to deliver fuel, supplies and equipment to the International Space Station. The Progress 8 spacecraft is scheduled to dock with the station early Saturday. The docking port that the Progress will use was vacated on Tuesday by the station’s previous Progress cargo ship, now filled with garbage. It was de-orbited and burned up in the Earth’s atmosphere.

A Russian Progress resupply craft was successfully launched today from the Baikonur Cosmodrome in Kazakhstan to bring fuel, supplies and equipment to the International Space Station.

The Progress 8 spacecraft lifted off on a Soyuz rocket at 12:37 a.m. CDT. About nine minutes later its solar rays and navigational antennas deployed in response to preprogrammed commands, and the umpiloted cargo carrier was safely in orbit.

Progress 8 is scheduled to dock with the space station early Saturday, where Expedition 5 crewmembers, Commander Valery Korzun, Astronaut Peggy Whitson and Cosmonaut Sergei Treschev, will begin unloading its cargo. The Progress can carry about 7,000 pounds into orbit, including fuel for the Zvezda Service Module’s attitude control thrusters.

A series of rendezvous burns by the Progress 8 engines over the next three days will result in its docking to the aft port of the Zvezda Service Module at about 1:25 a.m. CDT Saturday over Central Asia. That port was vacated Tuesday when the Progress 7 was undocked with its load of trash and deorbited to a fiery destruction in the Earth’s atmosphere.

Original Source: NASA News Release

NASA Finds Tiny Cracks in Shuttle Fuel Lines

NASA controllers decided to ground the shuttle fleet this week when they discovered tiny fuel line cracks. The first crack was uncovered during a routine examination of Atlantis, so the other shuttles were analyzed and additional cracks were found in Discovery as well. Industry experts applaud NASA’s decision to ground the fleet; since the Challenger disaster in 1986, NASA has put a greater emphasis on safety.

Open the pod bay door Universe Today

I think I’ve finally got everything working properly now, so I wanted to take moment and explain what happened Wednesday night (hereafter we’ll call it Evil Wednesday) when Universe Today took on a mind of its own and went on an email rampage. Around 8:00pm my time my Internet hosting provider started resending emails it had already sent through its mail system, including 12 versions of Universe Today. I contacted technical support and their only solution to stop this from happening was for me to delete the entire mailing list.

So I did (I had a backup). Then they recommended that I rebuild it again. So I did, which was when everyone on the list should have received a “Welcome to Universe Today” email. Don’t worry, you aren’t going to get an extra newsletter, you’re still just subscribed once. Unfortunately I think a few hundred people misunderstood, and unsubscribed from the newsletter. 🙁

My webhost accepted responsibility for the problem – it was totally their fault, not a virus, or problem on my end (whew). Unfortunately, they’re not entirely sure why it happened, but they’re still looking into it. So, there isn’t much I can do but hope that it doesn’t happen again.

Thanks for your support, here’s an adorable picture of my now 8-month old daughter to help distract you from the cramps in your delete finger.

Asteroid Narrowly Misses the Earth

An asteroid the size of a football field came extremely close to the Earth last week, and scientists didn’t even know until after it passed us by. Asteroid 2002 MN is 100 metres in diameter and passed by us at a distance of only 120,000km, less than one-third the distance from the Earth to the Moon. This is one of the closest near-misses ever recorded of a spacerock this size; had it actually struck the planet it would have cause considerable destruction and loss of life.

Endeavour Lands in California

After two extra days in space, Endeavour finally touched down at Edwards Air Force Base in California on Wednesday. The landing had been delayed because of thunderstorms at the Florida landing strip. During the shuttle’s 14 days in space, the astronauts delivered a new crew to the International Space Station and performed three spacewalks to install new hardware. The shuttle will now be mounted onto the back of a specially modified 747 and flown back to Florida to prepare for its next launch.

Endeavour in Space Another Day

Once again NASA postponed the landing of the space shuttle Endeavour because of foul weather in both Florida and California. The next opportunity will be on Wednesday, when the shuttle will try to land at Cape Canaveral at 1452 GMT (10:52am EDT). There’s one more window in Florida and three at California’s Edwards Air Force Base. The shuttle has enough supplies to remain in orbit until Thursday.

French Astronaut Gets Government Position

Image credit: ESA

Claudie Haigner?, an astronaut with the European Space Agency, has been appointed to the post of Minister for Research and New Technologies in the French government. She joined the European Astronaut Corps in 1999 and has been to space twice on board Russian Soyuz spacecraft – she was the first European woman to visit the International Space Station in 2001.

Claudie Haigner?, the ESA astronaut, has been appointed to the post of Minister for Research and New Technologies in the French government announced yesterday.

Claudie Haigner?, 45, with an outstanding ‘cursus honoris’, a doctor with a specialisation in rheumatology and a Ph.D in neurosciences, was selected in 1985 as a candidate astronaut by the French space agency, CNES. She has played a prominent role in the development of scientific applications of manned spaceflight and in fostering scientific relations with Russia. Mrs Haigner? is a permanent member of the French Academy of Technology and holds the honours of Officier de la L?gion d’Honneur and Chevalier de l’Ordre National du M?rite.

In 1999 she joined the European Astronaut Corps of the European Space Agency. She has taken part in two space missions with the Russians, ‘Cassiop?e’ in August 1996 and ‘Androm?de’ in October 2001. She was the first woman to qualify as a Soyuz Return Commander (July 1999), responsible for the three-person Soyuz capsule during a re-entry from space, and was the first European woman to visit the International Space Station (October 2001).

ESA’s Director General, Antonio Rodot?, expressed delight at this appointment, “In our ‘space world’ Claudie Haigner? has demonstrated really outstanding capabilities as a scientist as well as an astronaut during her time with us. This appointment honours the European Space Agency and puts Mrs Haigner? in a key position to shape the future of Europe’s science and technology. I wish her all the best in her new responsibilities.”

Original Source: ESA News Release

View of Colorado Fire from Space

Image credit: NASA

A new photo released from NASA’s Terra spacecraft shows the huge swath of destruction caused by the enormous fire in Colorado. The fire started on June 8, and has gone on to destroy more than 40,000 hectares. The image was acquired using Terra’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (Aster), one of five Earth imaging instruments on board the spacecraft. This photo was taken on morning of Sunday, June 16.

Thousands of acres of burned vegetation, along with recent hotspots, are visible in a new image of Colorado’s worst forest fire taken by NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (Aster).

Started on June 8, the Hayman forest fire continues to burn in the Pike National Forest, 57 kilometers (35 miles) south-southwest of Denver, Colo. According to the U.S. Forest Service, the fire has consumed more than 100,000 acres.

The image is available at:

http://www.jpl.nasa.gov/images/earth/usa/west.html.

Acquired Sunday morning, June 16, 2002, the Aster image shows active fires in red. The dark blue area is burned vegetation, and the green areas are healthy vegetation. Clouds are white. The blue cloud at the top center is smoke. The image covers an area of 32.2 by 35.2 kilometers (20 by 21.8 miles).

Aster is one of five Earth-observing instruments launched in December 1999 on NASA’s Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), Aster will image Earth for the next six years to map and monitor the planet’s changing surface. Japan’s Ministry of Economy, Trade and Industry built the instrument. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., is responsible for the American portion of the joint U.S./Japan science team that validates and calibrates the instrument and the data products.

Original Source: NASA/JPL News Release

Write Your Name on an Asteroid?

A Japanese spacecraft will give people an opportunity to land their name on an asteroid. Due for launch near the end of this year, the MUSES-C spacecraft will meet up with asteroid 1998 SF36 when it crosses the Earth’s orbit in 2005. It will land on the asteroid, collect samples which it will later return to Earth. As part of its mission, the spacecraft will deposit an aluminium foil sheet containing the names of hundreds of thousands of space enthusiasts. If you want to get your name on board, you have until July 5th.