New telescope will scan the skies for asteroids on a collision course with the Earth

This article was originally published at The Conversation. The publication contributed to Space.com's expert voice article: Op-Ed and Insights.

Around sunrise on February 15, 2013, an extremely bright object from another world was seen streaking across the sky before it exploded about 97,000 feet above the Earth's surface . The ensuing explosion damaged thousands of buildings and injured around 1,500 people in and around Chelyabinsk. Although it sounds like the first scene of a sci-fi movie, this invader was not an alien spaceship attacking humanity, but a 20-meter-wide asteroid that had crashed into the Earth.

What is disturbing is that As an astronomer, I study objects in the sky that change brightness on short time scales – observations that I'm having. uses to detect planets around other stars. Much of my research is to understand how we can better design and operate telescopes to monitor an ever-changing sky. This is important because the same telescopes that I use to explore other star systems are also designed to help my colleagues discover objects in our own solar system, such as asteroids colliding with the Earth.

Objects Near the Earth [19659006] A meteor is a piece of matter that enters the earth's atmosphere. Before Chelyabinsk's meteor knew of his disappearance on Earth, he was in orbit around our sun like an asteroid. These rocky objects are normally considered limited to the asteroid belt between Mars and Jupiter. However, there are a lot of asteroids throughout the solar system. Some, like Chelyabinsk's meteor, are known as Near Earth Objects (NEO).

The Chelyabinsk meteor probably comes from a group of near – Earth objects called Apollo asteroids, named after the 1862 Apollo asteroid. There are more than 1,600 Apollo asteroids known in the JPL Small-Body database that have earth-crossing orbits and are large enough (over 140 meters) to be considered potentially hazardous asteroids (PHAs). with the Earth would have devastated the affected area.

The scars of these past collisions are prominent on the moon, but the Earth also bears the marks of such impacts. The Chicxulub crater of the Yucatan Peninsula in Mexico was created by the Chicxulub asteroid that led to the extinction of the dinosaurs. The Barringer crater in Arizona is only 50,000 years old. The question is not whether a dangerously large asteroid will collide with the Earth, but when?

Threat Search

The US Government takes seriously the threat of a collision of asteroids. In Article 321 of the NASA Authorization Act of 2005, Congress asked NASA to develop an NEO search program. NASA has been tasked with identifying 90% of all near-Earth objects over 140 meters in diameter. Currently, they estimate that three quarters of the 25,000 PLWHA have not yet been found.

To achieve this goal, an international team of hundreds of scientists, including myself, is completing the construction of the Large Synoptic Telescope (LSST). in Chile, which will be an essential tool to alert us of PHAs.

With significant funding from the US National Science Foundation, LSST will seek PHAs during its mission of 10 years observing the same area of ​​the sky at one hour intervals in search of objects having changed position. Everything that moves in an hour must be so close that it is in our solar system. Teams led by researchers from the University of Washington and JPL both produced simulations showing that the LSST alone would be able to find about 65% of PLHIV. If we combine LSST data with other astronomical surveys like Pan-STARRS and Catalina Sky Survey, we think we can achieve this goal of discovering 90% of potentially dangerous asteroids.

Preparing to Avoid Disaster

The Earth and these asteroids are in orbit around the sun, just on different paths. The more the observation of a given asteroid is important, the more its orbit can be mapped and predicted accurately. The biggest priority, then, is to find asteroids that could collide with Earth in the future.

If an asteroid is on a collision course for hours or days before it happens, the Earth will not have many options. It's as if a car is suddenly withdrawing in front of you. There is little you can do. If, however, we find these asteroids years or decades before a potential collision, then we might be able to use the spacecraft to push the asteroid enough to change its path so that it and Earth do not collide

however, easier said than done, and currently no one really knows how an asteroid can be redirected. There have been several mission proposals from NASA and the European Space Agency to do this, but up to now, they have not gone through the initial stages of mission development.

The B612 Foundation, a private, not-for-profit group, also attempts money for a mission to redirect an asteroid, and they may be the first to attempt that if government space programs do not do it. Pushing an asteroid looks like a strange thing to do, but when we someday find an asteroid on a collision course with Earth, it may well be that this saves humanity.

Michael B. Lund, Postdoctoral Researcher, Department of Physics and Astronomy, Vanderbilt University

This article was published in Originally on The Conversation. Read the original article. Follow all the questions and debates of Expert Voices – and join the discussion – on Facebook, Twitter and Google +. The opinions expressed are those of the author and do not necessarily reflect the opinions of the publisher. This version of the article was originally published on Space.com