NEWARK, NJ - FEBRUARY 08: An Amtrak train waits in Newark Penn Station on February 8, 2011 in Newark, New Jersey. Amtrak, a government-owned corporation, has joined up with New Jersey's two U.S. senators to propose a new rail link to New York City under the Hudson River. The "Gateway Project", which was formally proposed on Monday, would include two tunnels under the Hudson River and increase the train traffic under the river from 62 trains per day to 92 and cost an estimated $13.5 billion. This plan is looked at as an alternative after New Jersey Governor Chris Christie killed another rail link plan last year after he deemed it too costly to New Jersey residents.  (Photo by Spencer Platt/Getty Images)
Dubbo, NSW, Australia
American Bison (Bison bison) at Western Plains Zoo.
Dubbo, NSW, Australia
White-Handed Gibbon (Hylobates lar) at Western Plains Zoo.
San Francisco's Bay Bridge at Night
A path of stairs lead through a lava tube  called Raufarholshellir in Iceland.
Jason punches through the snow on the slopes beneath Hraundrangi in northern Iceland.
A jagged string of peaks in Northern Iceland. The pointiest one, on the right is called Hraundrangi.
Grand Prismatic Spring - Midway Geyser Basin, Yellowstone National Park
NEWARK, NJ - FEBRUARY 08: An Amtrak train waits in Newark Penn Station on February 8, 2011 in Newark, New Jersey. Amtrak, a government-owned corporation, has joined up with New Jersey's two U.S. senators to propose a new rail link to New York City under the Hudson River. The "Gateway Project", which was formally proposed on Monday, would include two tunnels under the Hudson River and increase the train traffic under the river from 62 trains per day to 92 and cost an estimated $13.5 billion. This plan is looked at as an alternative after New Jersey Governor Chris Christie killed another rail link plan last year after he deemed it too costly to New Jersey residents. (Photo by Spencer Platt/Getty Images)
NEWARK, NJ - FEBRUARY 08: An Amtrak train waits in Newark Penn Station on February 8, 2011 in Newark, New Jersey. Amtrak, a government-owned corporation, has joined up with New Jersey's two U.S. senators to propose a new rail link to New York City under the Hudson River. The "Gateway Project", which was formally proposed on Monday, would include two tunnels under the Hudson River and increase the train traffic under the river from 62 trains per day to 92 and cost an estimated $13.5 billion. This plan is looked at as an alternative after New Jersey Governor Chris Christie killed another rail link plan last year after he deemed it too costly to New Jersey residents.  (Photo by Spencer Platt/Getty Images)
NEWARK, NJ - FEBRUARY 08: An Amtrak train waits in Newark Penn Station on February 8, 2011 in Newark, New Jersey. Amtrak, a government-owned corporation, has joined up with New Jersey's two U.S. senators to propose a new rail link to New York City under the Hudson River. The "Gateway Project", which was formally proposed on Monday, would include two tunnels under the Hudson River and increase the train traffic under the river from 62 trains per day to 92 and cost an estimated $13.5 billion. This plan is looked at as an alternative after New Jersey Governor Chris Christie killed another rail link plan last year after he deemed it too costly to New Jersey residents. (Photo by Spencer Platt/Getty Images)
See photo in original gallery.