The End of the Universe: Q & A with Astronomer Chris Impey

When itcomes to the end of the universe, Chris Impey has become something of anexpert.

In his book"How It Ends: From You to the Universe" (April 19, W.W. Norton &Company), the deputy head of the astronomy department at the University ofArizona in Tucson examines the science of endings ? from individuals togalaxies to the universe. He devotes particular attention to the numerous waysour solar system could meet its demise.

Between the threat of an asteroid impact, a nearby supernova explosion, theburnout of our sun, or a rip in space and time caused by our expandinguniverse, the outlook seems pretty grim. But, most of these events have almostno chance of occurring within our lifetime ? it will likely take more likemillions of years, Impey explained. And even then, it's not all doom and gloom.

Waxingphilosophical, Impey explores a whole host of possible endings, but imparts asimple message: In the face of such adversity, humans have an obligation tomaintain good cheer while on Earth.

SPACE.comchatted with Impey about what the future has in store, and whether we shouldfear it.

SPACE.com:"How It Ends" examines the science of endings. What got you interestedin this field?

Impey: There are very few people who doresearch on endings and astronomical endings, but it became a little sideinterest. I do cosmology, so my research is distant galaxies and quasars. I'm,in general, aware that this accelerating universe scenario raises someinteresting questions about what it's going to look like billions of years fromnow.

When I writea book, I want to be able to learn a lot of stuff, so I like the idea ofendings because I can go from how we die to howthe universe dies, and along the way learn a lot of biology and some of thesubjects I'm not as familiar with.

SPACE.com:Do you think we have a morbid fascination with endings?

Impey: I can understand the human nature ofit. We, in our culture, have these difficult problems like the economy andwhether our kids are going to get jobs, and whether the Earth is going to gettoo hot for us to live comfortably. In a sense, worrying about these big anddramatic endings, it's almost a relief.

Many of themare, of course, remote and not really a prospect that anyone has to reallyworry about day to day. It's not that they get gloomy or depressed by it, theyjust think: This is fascinating. The world could really end all these differentways. I wonder which one is going to be the way.

SPACE.com:From your book tours and all the lectures you've given, what type ofcatastrophic scenarios do people seem to fear the most?

Impey: People are always going to askquestions and talk about the thing that's been in the newspapers. A year ago,that would have been the Mayan prediction of the end in 2012. If there's beenany talk about asteroids or impacts, that is on peoples' minds, so I talk aboutthat.

In general,people are worried about pandemics and the fact that we could be wiped out bymicrobes, which of course, is a real concern. I'm usually prepared for thosekinds of questions. And, of course, from more recent news stories, people areworried that the LargeHadron Collider is going to kill us by making a black hole that will eateverything up.

SPACE.com:So if the Earth does not survive, is there somewhere else in the Milky Way wherehumans could live?

Impey: It's a good question, because at somepoint the sun will burn out. And even before it burns out, it will get hot enoughthat the oceans will boil, so we should consider that. There's no really goodreal estate in the solar system.

If [Jupiter'smoon] Europa was a little hotter, then it would become a nice water world, andyou could just build islands and live there, but it doesn't have a goodatmosphere.

Terra-formingMars is another thing that people have talked about ? what would it take tomelt the ice on Mars and then feed the atmosphere with gas and small plant lifeto create oxygen? I think, the cheapest, easiest scenario for that will cost$10 trillion and take a thousand years, so that's not an easy thing to doeither.

Beyond thesolar system, people are actually quite optimistic that AlphaCentauri, the nearest star, could have Earth-like planets. So, it'spossible that the nearest Earth or Earth-like planet might be only 4 or 5light-years away, which sounds good, but the cost and difficulty of getting alarge number of people there is, of course, crazy. Our technology is completelyinadequate.

It cost $50billion in present-day dollars to get a dozen people to the moon 40 years ago,and we haven't even been back. So, if you're talking about getting a vastnumber of people light-years away, that's not even on the horizon of ourtechnology. But of course, you're talking about a scenario that's millions ofyears away. If humans survive in any form, we'd presumably have much bettertechnology by then.

You canfollow SPACE.com Staff Writer Denise Chow on Twitter @denisechow.

Have a news tip, correction or comment? Let us know at community@space.com.