Solar flare. Image: NASA Goddard Space Flight Center

Cosmic cataclysms are regular events in everyday Universe. Fortunately, space is vast, so we still didn’t witness to such happening. For now, we are lulled in our blue marble. Nevertheless, we have to be aware of dangerous possibilities. Our technology is developing with each passing day, but still compared to the outer space, we are tiny and unprotected. So, what are the cosmic catastrophes that are quite possible that befall us one day?

Disturbance Of Oort Cloud Caused By Passing Star

The Oort Cloud is a spherical cloud of predominantly icy planetesimals that is believed to surround the Sun at a distance of up to around 100,000 AU. Basically, a thick bubble of icy debris that surrounds our solar system. If some star on its path, come too close to our Sun, it would cause the disturbance of Oort cloud, wich further could lead to the debris and comets shower. The effects could range from serious climate changes to the complete extinction of life on Earth.

Artistic conception puts solar system distances in perspective.
Artistic conception puts solar system distances in perspective. Image: NASA / JPL-Caltech

Asteroid Impact

Unfortunately, the dinosaurs were tragic witnesses of this cosmic event. Uncontrolled space rocks, that drifting in our neighborhood, are always a potential disaster for us. Some may have no harm to us at all, but some could be deadly. We have strategies for its avoidance, but we are still on a long shot with this.

Meteor hits Russia Feb 15, 2013

Gamma Ray Burst

Gamma rays are an extremely energetic form of electromagnetic radiation. The bursts are caused by events such as rapid rotation of supernova, the birth of a neutron star, collapsing into a black hole. The main danger comes from so-called afterglow which imitates extreme radiation. If gamma ray burst would happen in our local group, it might cause the destruction of the ozone layer and left us unprotected. Actually, we already have a potential star system that could provoke such event – WR104. We can’t predict when it will happen and when it does, where the radiation will go. Perhaps, if we are lucky enough, the Earth will be missed.

Pinkish gamma ray burst.
Typical gamma ray bursts release as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime. Image: NASA/Swift/Cruz deWilde

Vicinity of Supernova

Supernova is the last stage of star’s life. Their explosion happens approximately every 100 years in Milky Way. If we are far enough – no worries. But its velocity can be fatal due to radiation that would cause an explosion. Currently, our closest red giant is Betelgeuse, only 300 – 400 lightyears from us. However, astronomers calculated that as far as the supernova is at least 50 light years from us, we are safe.

Dust forming around a supernova explosion.
Dust forming around a supernova explosion. Image: ESO/M. Kornmesser

Expanding Sun

Our Sun will die. The death will be long and painful. We will not live enough to see its very end. The Earth will vanish even before Sun become a white dwarf. During its expansion, it will swallow Mercury and Venus. The Solar winds will slow down Eart, put it on spiral layouts and melt it. This cosmic event is estimated to happen in about 7.59 billion years.

Solar flare.
Solar flare. Image: NASA Goddard Space Flight Center