Asteroid Day 2020: Raising awareness about threat posed by near-earth asteroids, since 2016

In December 2016, the United Nations General Assembly declared June 30 as the International Asteroid Day, to be observed annually. The day is aimed at creating awareness among the people regarding the near-earth objects (NEO) that can be “potentially catastrophic threats” to our planet. Comets and asteroids constitute NEOs. According to the UN, the International Asteroid Day focuses on raising public awareness about the “asteroid impact hazard” and to inform the public about the “crisis communication actions to be taken at the global level in case of a credible near-Earth object threat”. [caption id=“attachment_8541001” align=“alignnone” width=“1280”] More than 100 years later, new patchy forest grows at the site of the massive 1908 Tunguska explosion. Image courtesy: Sovfot/Universal Images[/caption]

112 years ago today, an asteroid impact rocked Siberia

The UN General Assembly chose June 30 to mark the anniversary of the Tunguska Event in Russia. On 30 June 1908, an asteroid fell on the Podkamennaya Tunguska river area in Siberia, Russia. The impact left behind “little evidence of its origin except flattening 5,00,000 acres of uninhabited forest, scorching the land, creating glowing clouds and producing shock waves that were detected around the world”. This event is considered to be the most impactful asteroid impact event in recorded history. In order to highlight the threat that the NEOs pose, awareness about the rocky bodies is needed. According to the National Geographic, asteroids are basically “chunks of rock that measure in size from a few feet to several miles in diameter”. [caption id=“attachment_7323091” align=“alignnone” width=“1280”] Image of comet 67P taken on 30 July 2015 by the Rosetta mission’s NavCam instrument. Image: ESA[/caption] While most of the bigger asteroids are present in the asteroid belt between Mars and Jupiter, some occasional collisions or gravitational tugs send comets and asteroids toward the sun on “highly elliptical orbits, some close enough to Earth to pose a risk of impact”.

How are comets and asteroids different?

Comets tend to have “more chemical compounds” that vaporize when heated, such as water. They also travel in more elliptical orbits than asteroids do. Comets also appear fuzzier when observed through a telescope than asteroids do. Also read:  **It's Asteroid Day 2020: Why you should care, and how to catch live events on asteroids today** **Killer asteroid obliterates New York in planetary defense simulation exercise** MIT researchers develop 'decision map' that finds the best way to deflect incoming asteroid _World’s oldest asteroid strike in Western Australia might have caused a global thaw_ _Did asteroid, climate change really cause the mass extinction that took place 215 million years ago?_ _New type of Trojan asteroid discovered near Jupiter has an orbit like an asteroid but the tail of a comet_