Safe crash

The Galileo spacecraft launched in 1989 to survey Jupiter and four of its moons may be close to a fiery end. A NASA (National Aeronautic and Space Administration) panel has recommended that the spacecraft be allowed to crash into Jupiter's atmosphere in December 2002. This is to prevent it from crashing into Europa, satellite of Jupiter where scientists believe there is a subsurface ocean that could have life. The spacecraft has already outlived its expected life and researchers believe that soon it could become uncontrollable.

Greenland ice melts

Global warming is responsible for melting more than 50 billion tonnes of water per year from the Greenland ice sheet, leading to a 59 centimetres rise in global sea level over the last century.

Oh! zone

Following two winters of low ozone loss in the stratosphere, the Arctic is likely to have experienced record ozone destruction. The ozone layer thins out during spring but so far has never disappeared. Ozone losses of more than 60 per cent have occured at altitudes of around 18 km. This is one of the worst ozone losses at this altitude in the Arctic. "The ozone hole is already close to the deepest yet seen and there is still ozone destruction going on up there," says John Pyle of the European Ozone Research Coordinating Unit.

The planet up close

The space shuttle Endeavour has captured every corner of the Earth in amazing three-dimensional images. For 11 days, beginning January 31, the globe was swathed by radar waves so that scientists from National Aeronautics and Space Administration (NASA) in the US could obtain data for the most complete high-resolution maps of the planet ever designed.

The light show

What went wrong?

According to the panel commissioned by the National Space and Aeronautic Administration (NASA) to find out what went wrong with the Mars Polar Lander, has said that a confused sensor may have led the lander crashing into the Red Planet. NASA lost contact with the Mars Polar Lander on December 3, 1999, when it was due to land on Mars. Tests have revealed that deploying the spacecraft's landing gear might have fooled the sensor into thinking that the craft had landed. This may have led to a command to shut down the engines that should have, in fact, slowed the lander's descent.

Starry picture

Supernovae are among the most spectacular events in our Universe. In a very short period, a star gives out energy that is equivalent to the energy given out by a whole galaxy. Unfortunately, our knowledge about the violent processes druing a supernova is still very sketchy. Now, astronomers have put together a portrait of a star in our galaxy that blew up 300 years ago, revealing a supernova with parts of its deepest core hurled into space.

Promising rain

If a team of scientists are to be believed, it will rain even in the desert. A joint project of National Aeronautics and Space Research, USA, and the Israel Space Agency say seeding clouds with silver iodide can enhance precipitation by up to 13-14 per cent. "We can produce giant soluble particles by artificial means. It will be more effective increasing rainfall in individual clouds by as much as 40 per cent," according to Zev Levin of the department of geophysics and planetary sciences at Tel Aviv University. This can be done with dust particles or large salt particles, he added.

The core of a star

The Chandra space observatory, launched last month by the US National Aeronautical and Space Administration, has already started transmitting images. It has sent images of the heart of the Crab Nebula, a star that exploded in the 11 century, which was recorded by Chinese astronomers. The images show energetic material spinning in swirls around the stellar corpse at the nebula's centre. They reveal a bright ring that might be the long-sought power source pumping energy into the pulsar at the centre of the nebula ( Science , Vol 286, No 5438).

(W)hole truth

The ozone hole over Antarctica -- the region where the Earth-shielding ozone typically gets depleted -- is smaller this year than last year, says the National Aeronautic and Space Administration (NASA). "This Antarctic year's ozone depletion area, or ozone hole, is very large, but slightly smaller than that of 1998," said Richard McPeters, one of the scientists who used data from the Total Ozone Mapping Spectrometer aboard NASA's Earth Probe satellite to measure the hole.