Comet ISON breaks up into a cloud of debris after skimming the Sun.
The United Launch Alliance successfully launches the European Space Agency's Solar Orbiter (SolO) satellite from Cape Canaveral Air Force Station. The probe will study the Sun, and in particular its inner heliosphere.
NASA's "Parker Solar Probe" spacecraft becomes the closest ever sent to the sun, by passing 42.7 million km (26.6 million miles) from the sun's surface. The previous record was set in 1976 by the "Helios 2" spacecraft. Parker's elliptical orbit will eventually take it to within 6.1 million km (3.8 million miles) of the sun.
Scientists (in the article published in the journal "Atmospheric Chemistry and Physics") warn that the ozone layer that protects people from the sun's ultraviolet radiation is recovering only over less populated areas.
Astronomers announce that 2014 UZ224 is the third most distant Solar System object known from our Sun, currently over 90 times the Earth's distance from the Sun (90.8 AU or 8.44 billion miles), after Eris (96.2 AU) and V774104 (~103 AU).
An unusually large coronal mass ejection emitted by the Sun barely missed the Earth by nine days, dubbed the Solar storm of 2012. If it hit, it would have caused up to US$2.6 trillion in damages to electrical equipment worldwide.