It might seem as if astronomers and astrophysicists have had enormous success at unlocking the mysteries of space.
Impressive evidence has been gathered to support the theory that our universe was created about 13.7 billion years ago with an explosion of energy that eventually formed the innumerable galaxies still spinning away from one another to uncharted expanses of space.
We've discovered distant planets that might be friendly to life as we know it and have estimated distances to remote pulsing stars to help map the universe. We've assessed the power of black holes and remain awestruck by the extraordinary beauty of images of distant galaxies, young and old, captured by the Hubble Space Telescope.
But central mysteries of the universe remain unsolved, and from a scientific viewpoint, there are still more questions than answers. Most scientists would agree that we know very little about what really makes up our universe - and little about its origin and possible fate.
Once we thought the universe was filled with shining stars, dust, planets and galaxies. We now know that about 20 percent to 25 percent of the universe is made up of dark matter, a force that keeps stars speeding around galaxies, emits no light and bends space and time.
And dark matter is only part of the story. Scientists have recently discovered a more abundant and mysterious substance called dark energy that makes up 70 percent to 75 percent of the universe.
Dark energy's existence and the mysteries that surround it have prompted astronomers and physicists to fundamentally re-examine their theories.
Scientists generally agree that dark energy is accelerating the expansion of the universe but are sharply divided over other implications.
Some theorize that it signals the existence of parallel universes that may someday collide. Others say that, depending on what dark energy turns out to be, our visible universe might gradually disappear, or tear itself apart in a Big Rip, or collapse in a Big Crunch down to a universe the size of nothing, ready to be reincarnated in another Big Bang.
Now, researchers in Maryland and elsewhere are preparing proposals for a new space telescope aimed at exploring dark energy's secrets.
"It addresses arguably the biggest problem physics is facing right now," said Mario Livio, a senior astrophysicist at the Space Telescope Science Institute in Baltimore. "Dark energy makes up 74 percent of the universe, it's the dominant type of energy in the universe, and we haven't a clue of what it is."
Plans for a dark energy space telescope won major support this fall when a National Research Council panel recommended that NASA and the Department of Energy make it a top priority. Government scientists plan to formally call for proposals next year to build and operate a $600 million to $700 million dark energy telescope.
The Maryland team of astrophysicists that hopes to capture a NASA dark telescope contract includes astrophysicists from the Johns Hopkins University, Baltimore's Space Telescope Science Institute, the Goddard Space Flight Center and other institutions. The group is led by Charles Bennett, a professor of astrophysics at Hopkins.
For Maryland, winning the contract would mean added prestige for a scientific community that already employs hundreds of people who help operate the Hubble Space Telescope and are planning for launch of the James Webb Space Telescope.
Bennett is unsure how many scientists and researchers would be hired if they secure the contract. But it would guarantee some work not only leading up to the launch, tentatively slated for sometime around 2015, but for years of operations.
The Maryland group has avid competitors.
"It's always frustrating if you're the scientist planning these projects because we're always raring to go," said Saul Perlmutter, a researcher at the Lawrence Berkeley National Lab in California who is credited with co-discovering dark energy and is heading a team competing with Bennett's group.
NASA awarded the teams headed by Bennett and Perlmutter, along with a group from the National Optical Astronomy Observatory in Arizona, between $1.5 million and $2 million each last year to develop preliminary mission designs.
Six teams competed for the awards, but any number could submit proposals when a mission design contract is formally announced by NASA and the Department of Energy, said Jon Morse, NASA's director of astrophysics. NASA is expected to solicit design contract proposals by September 2008, he said.
Bennett and the dozen scientists on his team have spent much of the past two years drawing up preliminary plans. Being beaten by a competitor would be a blow.
"I don't know about devastating, but it would definitely be more fun to win than to lose," Bennett said.