GENEVA, SWITZERLAND – The 6,000-plus ton satellite that is expected to fall to Earth late Friday has gripped US media this week, and the frenzy of concern over where it will fall has extended to Italy. Civil protection authorities in northern Italy Friday told people the risk is greater in their area and they should stay home to avoid the possibility of falling debris.
Nasa, the US space agency, says the Upper Atmosphere Research Satellite is one of hundreds that return from space every year but this one is the size of a small van. Most of it will burn up during re-entry, but chunks weighing more than 150 kg could survive the fall. The odds of a person belong hit are nevertheless tiny, on the order of 0.03 percent. Italian authorities say the odds are 1.5 percent in the north of the country.
Civil protection authorities are warning Italians not to go near any pieces of the satellite they find, because they could emit toxic gases.
US media have made the story headline news all week. The satellite was launched in 1991. It has spent 7,317 days in space.
The Gravity Probe B results proving Einstein's theories on the geodetic and frame-dragging effects. (photo, ©Nasa)
Data from Nasa’s Gravity Probe B (GP-B), a satellite launched in 2004 to investigate two parts of Einstein’s theory of general relativity, confirms that he was right, Nasa announced 3 May. The final results published online in the journal Physical Review Letters were presented at a press conference in Washington DC Wednesday 4 May.
The first part of Einstein’s theory that the satellite was out to research is the geodetic effect, or the warping of space and time around a planet or a star. The second is frame-dragging, the amount of space and time that a spinning object pulls with it as it rotates.
“Imagine the Earth as if it were immersed in honey. As the planet rotates, the honey around it would swirl, and it’s the same with space and time,” says Francis Everitt, GP-B principal investigator at Stanford University in a Nasa press release. “GP-B confirmed two of the most profound predictions of Einstein’s universe, having far-reaching implications across astrophysics research. Likewise, the decades of technological innovation behind the mission will have a lasting legacy on Earth and in space.”
Links to other sites: BBC, Nasa, New York Times, Stanford
Earth's airglow, viewed from space by the tiny SwissCube satellite
Lausanne, Switzerland (GenevaLunch) – They won’t be competing with Nasa photography from space, but this doesn’t diminish the thrill for students at EPFL, the federal polytechnic institute in Lausanne, on seeing their first photo from space.
Students spent six years designing and building the tiny SwissCube satellite, which was launched 23 September 2009. It weighs only 854 grams and is 10cm3 in size.
It is designed to allow staff and students to study airglow, described by the university as ” a luminescent phenomenon in the planetary atmosphere caused by cosmic rays striking the upper atmosphere and chemiluminescence caused mainly by oxygen and nitrogen reacting with hydroxyl ions at heights of a few hundred kilometers.”
Video by the European Space Agency, 2007, on the project and the students’ work in the early stages
Video interview with Muriel Noca, 2011, on SwissCube’s findings
Moon craters (photo: Nasa)
The moon definitely has water, US agency Nasa announced 13 November, describing preliminary findings of its lunar crater observation and sensing satellite (Lcross). The satellite “plunged” into a crater of the south pole of the Moon 9 October 200. The water was found in the crater, which is permanently in shadow, as part of a hunt for ice. Nasa says the discovery “opens a new chapter in our understanding of the Moon.”
Swisscube, EPFL, 10cm2 and 83 grams
Lausanne, Switzerland (GenevaLunch) - Switzerland’s first-ever satellite has begun transmitting from space after its successful launch at 08:22 from India’s Sriharikota space station. The 833-gram, 10 cubic centimetre satellite began sending signals at 09:37. It is equipped with a telescope to allow staff and students to study airglow, described by the university as ” a luminescent phenomenon in the planetary atmosphere caused by cosmic rays striking the upper atmosphere and chemiluminescence caused mainly by oxygen and nitrogen reacting with hydroxyl ions at heights of a few hundred kilometers.”
The satellite was built by the EPFL in Lausanne as an educational project, with several government offices and companies as partners.
North Korea officially says it launched a satellite that is now “circling the earth transmitting revolutionary songs,” reports Reuters, but it has few believers, with the US, South Korea and Japan – over which the long-range rocket was launched – expressing outrage at the North’s behaviour, saying the launch appears to have been a ballistic missile test. The United Nations Security Council is meeting Sunday afternoon to discuss the launch but China and Russia, who have in the past supported North Korea, are calling for calm and restraint. The BBC refers to the activity as a failed launch, with the satellite not going into orbit and the US claiming payloads fell into the Pacific.
