HispanicBusiness

KILLER METEORITE

Myth: A large meteorite is destined to slam into the Earth in December, wiping out the inhabitants of the planet.

The Facts: The Earth could conceivably be struck by a large meteorite, but scientists agree that such a collision isn't going to happen in 2012. Earth's atmosphere is actually bombarded by meteors on a daily basis; basketball-size objects come in a couple of times a day, and objects the size of a Volkswagen come in every couple of weeks. But they burn up before reaching the Earth's surface.

Objects must be at least 40 meters in diameter to break through the atmosphere and cause ground damage, according to Yeomans. That only occurs about once every 500 years, he said.

"We know of no objects that are really of a concern to Earth, either this December or for the next several years," said Yeomans, manager of the near-Earth object project office at NASA's Jet Propulsion Laboratory.

The last big impact from a meteorite was 65 million years ago, leading to the extinction of the dinosaurs, according to Morrison. NASA now monitors the activity of large asteroids through a project called the "Spaceguard Survey," and provides data about incoming objects online. It has a catalogue of about 10,00 asteroids, with determined orbits.

"NASA is very aware of this issue and is making great strides to predict any large objects that are incoming," Yeomans said.

SOLAR FLARE

Myth: A gigantic solar flare will occur in December, wreaking havoc on the Earth by knocking out electronics. Alternatively, a tear in the earth's magnetosphere will expose the Earth to harmful radiation from the sun.

The Facts: Solar activity has a regular cycle, with peaks approximately every 11 years, according to NASA. Near these activity peaks, solar flares can cause some interruption of satellite communications.

The next solar maximum will occur in the 2012-2014 time frame, but it isn't expected to be particularly intense, according to NASA.

"This solar cycle is sort of the wimpiest solar cycle in the space age," said Guhathakurta, who studies space weather at NASA headquarters. "It is lower than what we had even expected."

In addition, NASA has developed tools to keep tabs on solar activity, and it doesn't look like a powerful solar storm will take place in December, Guhathakurta said. NASA can now monitor solar activity in real-time from different vantage points, and abnormal activity doesn't go unnoticed, she said.

If a solar region looks particular active, NASA has to ability to issue a warning to operators of potentially sensitive electronics, such as power grids, advising them to power down before impact.

Solar storms don't pose a direct physical threat to human beings on Earth, such as exposure to radiation or fire, Guhathakurta said, but they can severely damage electronics.

The magnetosphere is a projection of the Earth's magnetic field into space. It shields the Earth like a cocoon from the harmful radiation of the sun, enabling life to be generated on the planet. When radiation does breach the magnetosphere, it can propagate toward the planet, producing magnetic storms.

Particles from the sun can also create electromagnetic fluctuations that can interfere with communication tools and electronics. For example, it was a magnetic storm that led to a blackout in portions of Canada during the 1989 Hydro-Quebec power failure.

Engineers are learning how to build electronics that are protected against most solar storms, according to NASA.

"Yes, these particles can penetrate through our magnetosphere," Guhathakurta said, "but even that, we are able to guide people through..."



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