A year of brushes with extinction: 2019 saw a record 2,144 space rocks whiz past Earth
This year has been the year of asteroids. So far, 2,144 of such asteroids have hurtled past Earth, of which 175 approached the planet in November, according to the European Space Agency (ESA), which monitors and raises alarms of possible collisions.
With just days before the year comes to a close, asteroid enthusiasts should brace themselves for two other close and interesting approaches, says ESA. According to the agency, on December 20, a 300-metre-wide rock will advance towards the planet. Six days later, a slightly bigger space rock, measuring 400 metres will show up.
None of them are expected to put Earth's inhabitants in harm's way. They will be at a distance that measures 15 times the distance from the Earth to the Moon. But those that approach too close are generally small, say scientists, adding that some of them even manage to enter the atmosphere. Because their sizes are negligible, they are more likely to burn into a stream of dust and gas, as they enter the Earth's atmosphere at dizzying speeds, never really making contact with land or ocean, say experts.
For example, two asteroids came close to the Earth in November. In the first 10 days of November, these objects were at half a lunar distance away from Earth. If Near-Earth object's (NEOs) -- asterioids or comets -- orbit crosses the Earth's, and the object is larger than 140 meters across, it is considered a potentially hazardous object (PHO), which are tracked by NASA.
These objects pose a significant threat. NASA and ESA are keeping an eye on possible future collisions. Recently, NASA announced that it is planning to build and launch an asteroid-hunting space telescope. The telescope will see in the infrared light, picking up the heat signatures of small near-Earth asteroids.
To that end, the community is backing a proposal called the Near-Earth Object Surveillance Mission (NEOSM), which builds on an earlier concept called the Near-Earth Object Camera (NEOCam).
Thomas Zurbuchen, NASA's associate administrator for science, announced that the development of Near-Earth Object Surveillance Mission (NEOSM) will be launched before 2025, under the leadership of NASA's Jet Propulsion Laboratory in Pasadena, California.