Play the classic Asteroids game online. Sep 20, 2017 Asteroids are rocky worlds revolving around the sun that are too small to be called planets. They are also known as planetoids or minor planets. There are millions of asteroids, ranging in size. Asteroids are rich in precious metals and other metals, as well as water. Some asteroids are actually blown-out comets. The ices are gone, and all that’s left is the rocky material. Some asteroids have moons of their own! Most asteroids orbit the Sun in the Asteroid Belt, which lies between Mars and Jupiter.

May 03, 2019 The asteroid—nicknamed Apophis—will be as close as some of our satellites and only a few thousand miles away from the Earth’s atmosphere itself. That would make it one of the closest near-miss.
Asteroids are small, atmosphere-less rocky objects orbiting the Sun. Here are 10 things that you might not know about these planet-like celestial bodies that can crash into the Earth and create havoc. An artist's 3D rendering of an asteroid.

Time and again, asteroid impacts on Earth have scarred the surface of the blue planet, leaving behind massive craters. These are called impact events where asteroids coming from space enter the earth's atmosphere and collides with the earth's surface. These impact events may release enough energy which may be equal to a nuclear bomb. In modern history, the Tunguska event in Russia is a good example which occurred in 1908. This particular impact event flattened and burned about 80 million trees in an 830 square mile forest. Most of the time, asteroids also leave a deep gaping depression on the earth's surface.

Most Destructive Asteroid Impacts in Human History

Experts and scientist researchers have stated that in the past 600 million years, about 60 asteroids or similar objects of 3 miles or larger in size have hit the earth. Three ground impact events on land have been determined to have caused the mass extinction of life on the planet. There is also known evidence of ocean impacts. Time and again, it has been debated whether ocean impact events could cause a mega tsunami or just a mantle plume (volcanism). The following asteroid impact events created huge craters in the past and may have affected life on earth. First on the list is the massive 118.061-mile radius Vredefort Crater located in Free State, South Africa, which hit 2 billion years ago. Second is the 80.7783-mile radius Sudbury Basin located in Ontario, Canada, which hit 1.8 billion years ago. Third is the 55.9234-mile radius Acraman Crater in South Australia, Australia which hit Earth 580 million years ago. The fourth is the 25-74.5645-mile radius Woodleigh Crater in Western Australia, Australia which hit 360 million years ago. Fifth is the 62.1371-mile radius Manicouagan Crater in Quebec, Canada, which hit 215 million years ago. Sixth is the 43.496-mile radius Morokweng Crater in North West, South Africa, which hit 145 million years ago. Seventh is the 40.3891-mile radius Kara Crater in Nenetsia, Russia, which hit 70.3 million years ago. Eighth is the 106-186.411-mile radius Chicxulub Crater in Yucatan, Mexico, which hit 65 million years ago. This particular impact event has been confirmed as having caused mass extinction on earth at that time. Ninth is the 62.1371-mile radius Popigai Crater in Siberia, Russia, which hit 35.7 million years ago. Tenth on the list but as destructive is the 52.8166-mile radius Chesapeake Bay Crater in Virginia, the United States, which hit 35 million years ago.

Earth Impacts in the Future

In the possible event of an asteroid impact, the National Aeronautics and Space Administration (NASA) in the United States has a program called Sentry that uses the JPL Sentry System. It is a highly automated collision monitoring system that has been programmed to detect any future possibilities of an asteroid-earth collision. It also maintains and updates a catalog of asteroids that could hit the earth in the future. Among many negative things that some of these impact event collisions have triggered, the worst effects were the mass extinction events of life on earth. There is also a risk of future impact events that could cause huge natural upheavals like volcanism and mega tsunamis. There is also that possibility of a massive future hit that could trigger the shut down of the earth's magnetic field.

One of Earth's greatest threats and mankind's biggest fears is the catastrophic impact of an asteroid and with good reason. Evidence remains of the devastation such impacts from the early history of Earth's formation caused. None so frightening as the impact that nearly wiped out all life a mere 66 million years ago.

Aside from the asteroid that reduced the dinosaur population to extinction, two events in recent history have given credence to the monitoring and calculating of asteroids within our solar system. The Tunguska event in 1908 which destroyed over 1290 km (800 miles) worth of forest and the Chelyabinsk Meteor in 2013 who snuck into Earth's atmosphere undetected. Neither made landfall and exploded shortly before hitting the Earth but the devastation they created makes many question, what if they had hit the ground?

Today, we have several monitoring programs such as NASA's Near-Earth Objects Observation program which catalogs and calculates the trajectories of any potential threats to Earth. Large telescopes such as the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) watch the skies diligently, keeping track of all objects in our skies to make sure that if there is a threat, we would see it coming and be capable of minimizing or eliminating the devastation it could cause on impact.

List of the largest asteroids

Currently, the largest asteroids listed to date primarily exist within the asteroid belt between Mars and Jupiter. Here is a list of the 15 largest asteroids in order of size.

1 Ceres — although it is now listed as a dwarf planet, it is still considered the largest asteroid in our solar system. It orbits the sun within the asteroid belt (occasionally called the Ceres asteroid belt) in between Mars and Jupiter. It is about 945 km (587 miles) in size making it the largest asteroid.

Color image of Vesta taken by Dawn /unmannedspaceflight.com

4 Vesta — the second-largest asteroid in the solar system at 525 km (326 miles) in size and is also located in the asteroid belt between Mars and Jupiter. It contributes about 9% of the total mass of the entire belt. It has an orbital time of 3.63 years and it has an axial tilt of 29 degrees. This asteroid is on a list of objects that are under consideration as a dwarf planet.

2 Pallas — covers about 7% of the total mass of the asteroid belt and is the third largest asteroid in the solar system at 512 km (318 miles) in size. It's on the list of discovered objects for consideration as a dwarf planet (along with Sedna, Orcus, Quaoar, 2002 TX 300, 2002 AW 197, Varuna, Ixion, Vesta, and Hygiea) but at this time it is still considered an asteroid.

10 Hygiea — is the fourth largest asteroid in our solar system at about 350 to 500 km (217 to 300 miles) in size. It is also under consideration as a dwarf planet versus an asteroid due to its mass and shape. It is a C-type asteroid because it consists primarily of a carbon type surface.

704 Interamnia — at 350 km (217.48 miles) in diameter, taking up 1.2% of the total mass of the belt, 704 Interamnia is the fifth largest asteroid in the solar system. Because it is an F-type asteroid with a low albedo very little study can be done, it is too difficult to see.

52 Europa — is an asteroid located within the asteroid belt. This asteroid is about 315 km (195 miles) in diameter with a mass of 3.27Ãƒâ€”1019 kg. It is a C-type asteroid making it very dark in appearance.

A sequence of images of asteroid 511 Davida /keckobservatory.org

511 Davida — this asteroid's estimated at 270 to 310 km (167 to 192 miles) in diameter and covers 1.5% of the total mass of the belt. Its low albedo of 0.054–0.066 makes it pretty dark and difficult to see. It is a C-type asteroid which means it has a carbonaceous compound which attributes to its darkness.

Adaptive Optics observations of 87 Sylvia, showing its two moons, Remus and

Most Destructive Asteroid Impacts in Human History

Earth Impacts in the Future

Contents

List of the largest asteroids