***On the morning of February 15, 2013, an unusually bright object appeared in the sky, which exploded about 30 kilometers above the Earth's surface. The resulting explosion destroyed thousands of buildings and injured nearly 1,500 people in Chelyabinsk and the surrounding area. It sounds like a sci-fi movie scene. It is worrying that this 20-meter-long asteroid has gone unnoticed.***

*Construction of the LSST Telescope, Cerro Pachón, Chile*
![a.jpg](https://cdn.steemitimages.com/DQmVwpMvFsfEgULuZARnL9qPUQ4pyuMDZ3DmoVtvX4rq23u/a.jpg)
*By LSST Project/NSF/AURA* [link](https://gallery.lsst.org/bp/#/folder/3989372/71658815) *[CC BY-SA 4.0 license]*

Meteor is a cosmic rock that enters the Earth's atmosphere. Before the Chelyabinsk meteor fell to Earth, it orbited our Sun as a small asteroid. Such objects usually circulate in the asteroid belt between Mars and Jupiter. There are, however, many asteroids circling outside this belt. Some, like the Chelyabinsk meteor, are known as objects close to the Earth. It probably came from a group of objects called Apollo asteroids, named after the 1862 Apollo asteroid. There are more than 1600 known Apollo asteroids in the NASA database that have orbits that can intersect the Earth's path and are large enough (over 140 meters) that they are considered potentially dangerous. Their collision with the Earth would destroy the region's size area. Impact traces are visible on the moon, but the Earth also has traces of such strokes. **Chicxulub Crater** on the Mexican Yucatan Peninsula was created by an asteroid that led to the extinction of dinosaurs. **Barringer Crater** in Arizona is only 50,000 years old. The question isn't whether a dangerously large asteroid will collide with Earth, but **when**...

*Artistic vision of asteroid impact*
https://upload.wikimedia.org/wikipedia/commons/0/05/Planetoid_crashing_into_primordial_Earth.jpg
*By Don Davis (work commissioned by NASA)* [link](https://commons.wikimedia.org/wiki/File:Planetoid_crashing_into_primordial_Earth.jpg) *[Public domain]*

The US government is serious about the danger of collision with an asteroid. Congress required NASA to develop a search program for dangerous NEO objects. NASA received the task of identifying 90 percent of all objects with a diameter of more than **140 meters**. Currently, they estimate that 75% of them have not yet been found. To achieve this goal, an international team of hundreds of scientists completes the construction of the **Large Synoptic Survey Telescope** (LSST) in Chile, which will be an indispensable tool to warn us of potentially dangerous cosmic rocks. The telescope will look for threats during a 10-year mission, observing the same sky area in hourly intervals, searching for objects that have changed their location. LSST alone will be able to find about 65 percent of dangerous objects. Once LSST data is combined with others, it will be possible to detect up to 90 percent of potentially dangerous asteroids, meaning NASA will meet its obligations to the US government.

# <center> *Greetings to lovers of Astronomy!* </center>
#### <center> *References:* </center>

<center>**[New Telescope Will Scan The Skies for Asteroids on Collision Course with Earth](https://www.space.com/41050-new-telescope-will-scan-the-skies-for-asteroids-on-collision-course-with-earth.html)*</center>
<center>*[Large Synoptic Survey Telescope](https://en.wikipedia.org/wiki/Large_Synoptic_Survey_Telescope)*</center>
<center>*[Chelyabinsk meteor](https://en.wikipedia.org/wiki/Chelyabinsk_meteor)*</center>
<center>*[Chicxulub crater](https://en.wikipedia.org/wiki/Chicxulub_crater)*</center>
<center>*[Meteor Crater](https://en.wikipedia.org/wiki/Meteor_Crater)*</center>
<center>*and my knowledge...</center>

<center>*All rights reserved by @astromaniac 2018*</center>

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