In this April 28, 2015 file photo, heads of tuna on a cart are carried by a fish dealer after the day's auction at Tsukiji Wholesale Market in Tokyo. In one of the biggest of Japan's many New Year holiday rituals, early on Tuesday, January 5, 2016, Tokyo's Tsukiji market will auction off with much fanfare a huge, glistening tuna, likely destined for one of the big sushi chains. If all goes as planned, it will be the last such auction at 80-year-old Tsukiji. (Photo by Shuji Kajiyama/AP Photo)

“The Sloan Digital Sky Survey III (SDSS-III) has released the largest-ever three-dimensional map of massive galaxies and distant black holes, which will help astronomers explain the mysterious “dark matter” and “dark energy” that scientists know makes up 96 percent of the Universe”. – SDSS-III

Emily Hasler, an English Heritage employee at Charles Darwin's home, Down House, cleans a rabbit bone in his old study on April 2, 2011 in Downe, England. Staff at the house are cleaning and preparing the property ahead of their peak visitor season. The house contains the study where Darwin wrote “On the Origin of Species”, as well as family rooms and an extensive garden that inspired the renowned scientist. (Photo by Oli Scarff/Getty Images)

A reveler waves a gay pride flag in front of the historic gay bar The Stonewall after the passing of a bill legalizing gay marriage in New York State on June 24, 2011 in New York City. New York State now joins Connecticut, Massachusetts, New Hampshire, Vermont, Iowa and Washington, D.C. in legally recognizing gay marriage. (Photo by Spencer Platt/Getty Images)

A cleaning staff waers protective gear to disinfect a metro carriage as a prevemtive measure against the spreading of the COVID-19 coronavirus in Addis Ababa, Ethiopia, on March 20, 2020. African countries have been among the last to be hit by the global COVID-19 coronavirus epidemic but as cases rise, many nations are now taking strict measures to block the deadly illness. (Photo by Michael Tewelde/AFP Photo)

The Greyfriars Bobby statue is pictured wearing a mask as the spread of the coronavirus disease (COVID-19) continues, in Edinburgh, Scotland, Britain, March 23, 2020. (Photo by Russell Cheyne/Reuters)

A man carrying vegetables is stopped by police at a barricade on a road during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19) in Chennai, India, March 25, 2020. (Photo by P. Ravikumar/Reuters)

South Korean environmental activists wearing masks symbolizing the coronavirus attend a prevention campaign as South Koreans take measures to protect themselves against the spread of coronavirus (COVID-19) on March 30, 2020 in Seoul, South Korea. South Korea has called for expanded public participation in social distancing, as the country witnesses a wave of community spread and imported infections leading to a resurgence in new cases of COVID-19. According to the Korea Center for Disease Control and Prevention on Monday, 78 new cases were reported. The total number of infections in the nation tallies at 9,661. (Photo by Chung Sung-Jun/Getty Images)