The Tunguska event was a large explosion that occurred near the Tunguska River, in where is now Russia. The explosion occurred at an altitude of 5–10 kilometres (3–6 mi) by a stony asteroid that is believed to have burst in the air rather than hitting the surface.

Since the 1908 explosion, there have been an estimated 1,000 scholarly papers (mainly in Russian) published on the Tunguska explosion. In 2013, a team of researchers led by Victor Kvasnytsya of the National Academy of Sciences of Ukraine published analysis results of micro-samples from a peat bog near the blast epicenter showing fragments that may be of meteoric origin.

Estimates of the energy of the blast range from as low as three to as high as 30 megatons of TNT. The energy of th ...

A promising new drug called baloxavir marboxil (Xofluza) developed in Japan has been shown to stop the flu virus from spreading 24 hours after intake.

The drug interferes with influenza A and influenza B's main replication process instead of inhibiting the neuraminidase enzyme, as accomplished by previous drugs such as oseltamivir (Tamiflu) and zanamivir (Relenza). As shown in the illustration, viral neuraminidase sits on the surface of influenza viruses and enables it to be released once reproduced within the infected host cell.

Xofluza accomplishes its mode of action by inhibiting the cap-dependent endonuclease activity of the viral polymerase. It achieves this by inhibiting the process known as cap snatching, which is a mechanism expl ...