Four pillars of light from the 4 Laser Guide Star Facility on ESO's Very Large Telescope (VLT) are shown reaching into the Chilean night sky in this image from ESO Photo Ambassador Fred Kamphues, on September 2, 2016. The lasers are a key part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal in Chile, the home of the VLT. (Photo by F. Kamphues/ESO)

People gather at the site of a bomb explosion in Sanaa December 23, 2014. Five bombs exploded on Tuesday in Sanaa's old quarter, where many supporters of the Shi'ite Muslim Houthi group live, killing at least one person and wounding another, a Yemeni security official said. No one has claimed responsibility for the attacks, but the Houthis have been fighting the Sunni Islamist militant al Qaeda group and allied tribesmen since its gunmen captured Sanaa in September and forced the resignation of a government they had long seen as corrupt. (Photo by Khaled Abdullah/Reuters)

People gather at the site of a train derailment near Beni Suef, Egypt, Thursday, February 11, 2016 that injured dozens of people were injured as it was traveling north toward Cairo. Railroad accidents due to negligence are common in Egypt. Egyptians have long complained that the government has failed to deal with the country's chronic transport problems. (Photo by Samer Abdallah/AP Photo)

A Kenyan Red Cross personnel and a volunteer console a relative of a victim, at the site of a building collapse in Nairobi, Kenya, Saturday, April 30, 2016. A six-story residential building in a low income area of the Kenyan capital collapsed Friday night under heavy rain and flooding, killing at least seven people and injuring over 100 others, Kenyan officials said. (Photo by Sayyid Abdul Azim/AP Photo)

Covered in prayer shawls, Ultra-Orthodox Jewish men participate in a blessing during the holiday of Sukkot, in front of the Western Wall, the holiest site where Jews can pray in Jerusalem's Old City, Wednesday, September 30, 2015. The Cohanim, believed to be descendants of priests who served God in the Jewish Temple before it was destroyed, perform a blessing ceremony of the Jewish people three times a year during the festivals of Passover, Shavuot and Sukkot. (Photo by Oded Balilty/AP Photo)

A Palestinian protester sets fire to himself as he throws a molotov cocktail during clashes with the members of the Israeli armed forces in the West Bank city of Hebron, 13 October 2015. The past 12 days have seen the worst spell of street violence in Israel and the Palestinian areas in years, stirred in part by Muslim anger over perceived changes to the status quo observed at a disputed Jerusalem holy site. Sixteen Palestinians from the West Bank and Jerusalem have been killed, but more than half of them have been attackers shot dead after or during attempts to stab Israelis. (Photo by Abed Al Hashlamoun/EPA)

Photo taken on November 5, 2015 shows flood in Bento Rodrigues, a town in the southeastern Brazilian state of Minas Gerais, after a dam at a mining waste site burst early Thursday. An iron ore tailings dam in the southeast Brazilian state of Minas Gerais collapsed Thursday, killing at least 15 people, according to local media reports. (Photo by Agencia Estado/Xinhua Press/Corbis)

An employee holds a plant with roots at the Plant Advanced Technologies (PAT) company greenhouse in Laronxe near Nancy, Eastern France, June 19, 2015. The farmers employed at the site in Laronxe are growing plants in a special way with a view to “milking” them for use in medicines, cosmetics and agrochemicals. Several major brands, including Germany's BASF and France's Chanel, have teamed up with Plant Advanced Technologies (PAT) in the hope of securing privileged access to the so-called “biomolecules” it extracts through the use of a patented technique. (Photo by Vincent Kessler/Reuters)