How to defend the Earth from asteroids

At 17-20 meters across, the Chelyabinsk meteor caused extensive damage and damage when it exploded on Earth's atmosphere in February 2013.

To prevent another such impact, Amy Mainzer and colleagues use a simple yet ingenious way to spot these tiny near-Earth objects (NEOs) as they hurtle towards the planet. She is the principal investigator of NASA's asteroid hunting mission at the Jet Propulsion Laboratory in Pasadena, California, and will outline the work of NASA's Planetary Defense Coordination Office this week at the American Physical Society April Meeting in Denver-including her team's NEO -recognition method how it will help the efforts to prevent future Earth impacts.

"If we find an object only a few days ago, it is much more important for our choices, we are focused on finding NEOs when they are further away from Earth, providing the maximum amount of time and a wider aperture. range of mitigation possibilities, "Mainzer said.

But it's a difficult task-like spotting in the morning, Mainzer explained. "NEOs are intrinsically faint because they are mostly really small," she said. "Add to this the fact that some of them are a little bit like a printer,"

Mainzer's team at JPL / Caltech has raised a characteristic signature of NEOs-their heat. Asteroids and comets are warmed by the sun and so glow brightly at thermal wavelengths (infrared), making them easier to spot with the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) telescope.

"With the NEOWISE mission we can spot objects of their surface color," Mainzer said.

Discovering NEO surface properties provides an understanding of how to be effective in the field of defense against Earth-threatening NEO.

For instance, one defensive strategy is to physically "nudge" an NEO away from an Earth impact trajectory. But to calculate the energy required for the nudge, details of NEO mass, and therefore size and composition, are necessary.

Astronomers also think that examining the composition of asteroids will help to understand how the solar system was formed.

"These objects are intrinsically interesting because they are thought to be original in nature," said Mainzer. "One of the things we're finding that NEOs are pretty diverse in composition."

Mainzer is here to help you in your search for NEOs. "We are proposing to NASA to a new telescope, the Near-Earth Camera Object (NEOCam), to do a much more comprehensive job of mapping asteroid locations and measuring their sizes," Mainzer said.

NASA is not the only space agency trying to understand NEOs. For instance, the Japan Aerospace Exploration Agency's (JAXA's) Hayabusa 2's mission plans to collect samples from an asteroid. And in her presentation Mainzer will explain how NASA works with the global space community in an international effort to defend the planet from NEO impact.