NASA HubbleSite: HST Images as Wallpaper

HubbleSite - Wallpaper

Nasa SOHO Spacecraft: Nearing optimum position

An artist's impression of STEREO spacecraft surrounding the Sun.

NASA's twin STEREO probes moved into position on opposite sides of the sun, and they are now beaming back uninterrupted images of the entire star - front and back.

"For the first time ever, we can watch solar activity in its full three-dimensional glory," says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.

Four years after launch NASA's two STEREO spacecraft are now 180 degrees apart and able to image the entire Sun.
Picture: NASA

Car-Size Asteroid Pass Close by Earth

This NASA plot shows the Feb. 9, 2011 flyby of the asteroid 2011 CA7 as it passes close by Earth. The asteroid poses no threat of impacting the planet. NASA/JPL View full size image

An asteroid about the size of a car will pass close by Earth Wednesday (Feb. 9), the second space rock in five days to fly near – but pose no threat of hitting – our planet.
The asteroid is called 2011 CA7 and will fly within 64,300 miles (103,480 kilometers) of Earth tomorrow, according to an alert from NASA's Asteroid Watch program. It is about 9 1/2 feet across (nearly 3 meters) and was discovered by astronomers earlier this month.
The asteroid will make its closest pass by Earth at around 2:25 p.m. EST (1925 GMT), according to the small-body database overseen by NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Learning Difficulties: Exposure to Pesticides in Womb

Babies exposed to high levels of pesticides while in the womb may suffer from learning problems, a new study suggests.

The study focused on a chemical called permethrin, one of the pyrethroid pesticides, commonly used in agriculture and to kill termites, fleas and household bugs, says lead author Megan Horton of the Columbia Center for Children's Environmental Health. 

Most of the pregnant women in this New York-based study were exposed by spraying for cockroaches.

Permethrin — among the most commonly detected pesticides in homes — is being used more often today as older organophosphorous pesticides are phased out because of concerns that they harm brain development, says Horton, whose study is being published today in Pediatrics.

Researchers measured 348 pregnant women's exposures by asking them to wear backpack air monitors, Horton says. Researchers followed the women and their children for three years.

Children exposed to the highest pesticide levels before birth were three times as likely to have a mental delay compared to children with lower levels, the study says. 

Children with the highest prenatal exposures also scored about 4 points lower on an intelligence test, the Bayley Mental Developmental Index. That test has a mean score of 100, with most people's scores falling within 15 points of that range.

That's about the same intelligence loss caused by lead, says Philip Landrigan, a pediatrics professor and environmental health expert at New York's Mount Sinai School of Medicine.

Pyrethroid pesticides kill bugs by "being toxic to the developing brain," Landrigan says. The results are "very believable and should be taken seriously," Landrigan says.

Because the study is the first to link permethrin with brain damage, researchers need to conduct additional studies before concluding that the pesticide really harms the brain, says Mary Fox, an assistant professor at John Hopkins' Bloomberg School of Public Health.

Even without definitive data, however, Fox says it makes sense for pregnant women to reduce their exposure to bug sprays and other pesticides.

To control bugs, for example, she suggests fixing water leaks, keeping food tightly covered and, if necessary, spraying outside instead of inside the home.

NASA WISE Image: An Explosion in Jellyfish Nebula

This oddly colourful nebula is the supernova remnant IC 443 as seen by NASA's Wide-field Infrared Survey Explorer, or WISE.

Also known as the Jellyfish Nebula, IC 443 is particularly interesting because it provides a look into how stellar explosions interact with their environment.

Like other living creatures, stars have a life cycle -- they are born, mature and eventually die. The manner in which stars die depends on their mass.

Stars with mass similar to the sun typically become planetary nebulae at the end of their lives, whereas stars with many times the sun's mass explode as supernovae.

IC 443 is the remains of a star that went supernova between 5,000 and 10,000 years ago.

The blast from the supernova sent out shock waves that traveled through space, sweeping up and heating the surrounding gas and dust in the interstellar medium, and creating the supernova remnant seen in this image.

What is unusual about the IC 443 is that its shell-like form has two halves that have different radii, structures and emissions.

The larger northeastern shell, seen here as the violet-coloured semi-circle on the top left of the supernova remnant, is composed of sheet-like filaments that are emitting light from iron, neon, silicon and oxygen gas atoms, in addition to dust particles, all heated by the blast from the supernova.

The smaller southern shell, seen here in a bright cyan colour on the bottom half of the image, is constructed of denser clumps and knots primarily emitting light from hydrogen gas and heated dust.

These clumps are part of a molecular cloud, which can be seen in this image as the greenish cloud cutting across IC 443 from the northwest to southeast.

The colour differences seen in this image represent different wavelengths of infrared emission.

The differences in colour are also the result of differences in the energies of the shock waves hitting the interstellar medium.

The northeastern shell was probably created by a fast shock wave (223,700 miles per hour), whereas the southern shell was probably created by a slow shock wave (67,100 miles per hour).

Image Credit: NASA/JPL-Caltech/UCLA

Möbius Strip Hearts For Valentine's Day

A view of the Tropical Cyclone Yasi as it moves over Australia's Queensland.

This picture was taken by ESA's ISS Astronaut Paolo Nespoli through the Cupola window.