University of Utah image of a map of the northern sky showing the "hot spot" where scientists detected an unusual concentration of high energy cosmic rays. PRESS ASSOCIATION Photo. Issue date: Tuesday July 8, 2014. A mysterious "hot spot" in the sky is emitting unusual numbers of powerful cosmic rays, say scientists. The discovery may shed new light on the origin of ultra-high energy cosmic rays, which still cannot be fully explained. The hot spot is centred two hand-widths below the "handle" of the Big Dipper, or Plough, an arrangement of seven stars within the Great Bear constellation.

Ben Stokes/University of Utah/PA

University of Utah image of a map of the northern sky showing the ‘hot spot’ where scientists say they are detecting an unusual concentration of high energy cosmic rays

Passengers travel on an overcrowded train at Loni town in Uttar Pradesh...Passengers travel on an overcrowded train at Loni town in the northern Indian state of Uttar Pradesh July 8, 2014. On Tuesday, Indian Prime Minister Narendra Modi's new government will unveil its maiden railways budget, with expectations high that he will offer bold plans to improve the service - a lifeline for 23 million Indians every day.

Anindito Mukherjee/Reuters

Passengers travel on a train at Loni town in the northern Indian state of Uttar Pradesh. India is to open up its sprawling colonial-era railway network to private investors in one of recently elected premier Narendra Modi’s first moves to meet election promises of boosting economic growth in the subcontinent.

A monsoon lightning storm strikes over the Mandalay Bay Resorts and Casino and Luxor hotels in Las Vegas, Nevada late July 7, 2014. Monsoon storms are forecast for the the rest of the week in the Nevada and Arizona states.  The Luxor Sky Beam can be seen shining into the sky from the top of the hotel's pyramid structure.

Gene Blevins/Reuters

A monsoon lightning storm strikes over the Mandalay Bay Resorts and Casino in Las Vegas, Nevada. Monsoon storms are forecast for the rest of the week in Nevada and neighbouring Arizona.

A man walks past a destroyed railroad bridge which fell over a main road leading to the eastern Ukrainian city of Donetsk, near the village of Novobakhmutivka...A man walks past a destroyed railroad bridge which fell over a main road leading to the eastern Ukrainian city of Donetsk, near the village of Novobakhmutivka, north of Donetsk July 7, 2014. Ukraine's richest man pleaded with the government on Monday not to bomb Donetsk, a city of a million people where hundreds of heavily armed pro-Russian rebels have vowed to make a stand after losing control of their bastion in the town of Slaviansk.

Maxim Zmeyev/Reuters

A man walks past a destroyed railroad bridge which fell over a main road leading to the eastern Ukrainian city of Donetsk, near the village of Novobakhmutivka, north of Donetsk

Relatives of Palestinian militant Marwan Sleem mourn during his funeral in the central Gaza Strip July 7, 2014. Israel killed two Palestinian militants, one of them Sleem, and wounded a third in one of about a dozen air strikes in response to rocket fire at southern Israeli towns. Hospital officials confirmed the fatalities, and the Israeli military confirmed it had bombed central Gaza. Israeli air strikes killed seven Hamas militants in the Gaza Strip on Monday, the Islamist group said, in the deadliest attacks in a surge of violence exacerbated by the kidnapping and killing of three Israeli youths and a Palestinian teen.

Mohammed Salem/Reuters

Relatives of Palestinian militant Marwan Sleem mourn during his funeral in the central Gaza Strip on Monday. After an Israeli air strike on Gaza killed seven members of the militant Islamist group Hamas, the group vowed to retaliate in a move that will raise fears of a further escalation in Arab-Israeli hostility.

Visitors stand watch blue fin tunas in a 2,200-ton tank at Tokyo Sea Life Park in Tokyo, Monday, July 7, 2014. The tank is designed to create artificial flow of the ocean to keep the fish alive.

Koji Sasahara/AP

A visitor watches blue fin tunas in a 2,200-tonne tank at Tokyo Sea Life Park on Monday.

Soldiers wave during a visit by North Korean leader Kim Jong Un to inspect the defence detachment on Ung Islet, which is defending an outpost in the East Sea of Korea, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang July 7, 2014.

KCNA/Reuters

Soldiers wave during a visit by North Korean leader Kim Jong Un to inspect the defence detachment on Ung Islet, which is defending an outpost in the East Sea of Korea

An antique car drives down Main street during a July Fourth parade in the village of Barnstable, Massachusetts July 4, 2014. Barnstable, which is located on Cape Cod in Massachusetts and was first settled in 1639, is celebrating its 375th anniversary in 2014.

Mike Segar /Reuters

An antique car drives down Main street during a July Fourth parade in the village of Barnstable, Massachusetts. Barnstable, which is located on Cape Cod in Massachusetts and was first settled in 1639, is celebrating its 375th anniversary

Joe Giddens/PA

A festival goer enjoys herself in the crowd during day one of the Wireless Festival at Perry Park, Birmingham on Friday

Polo players Andy Burgess (R) riding Tonka Rob Brockett riding Torda (L) and Ben Marshall (C) riding Shriva practice for the beach polo competition being held on the beach at Watergate Bay, near Newquay this weekend on July 4, 2014 in Cornwall, England. The players were practicing ahead of this weekend's 8th annual Veuve Clicquot Polo on the Beach at Watergate Bay, north Cornwall, which is taking place tomorrow and Sunday which attracts thousands of spectators to the beach and features some of England's top international players competing in a series of matches.

Matt Cardy/Getty Images

Polo players Andy Burgess (R) riding Tonka Rob Brockett riding Torda (L) and Ben Marshall (C) riding Shriva practice for the beach polo competition being held on the beach at Watergate Bay, near Newquay this weekend on Friday in Cornwall, England