When it comes to the end of the universe, Chris Impey has become something of an expert.

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 of Arizona in Tucson examines the science of endings ? from individuals to galaxies to the universe. He devotes particular attention to the numerous ways our solar system could meet its demise.

Between the threat of an asteroid impact, a nearby supernova explosion, the burnout of our sun, or a rip in space and time caused by our expanding universe, the outlook seems pretty grim. But, most of these events have almost no chance of occurring within our lifetime ? it will likely take more like millions of years, Impey explained. And even then, it's not all doom and gloom.

Waxing philosophical, Impey explores a whole host of possible endings, but imparts a simple message: In the face of such adversity, humans have an obligation to maintain good cheer while on Earth.

SPACE.com chatted with Impey about what the future has in store, and whether we should fear it.

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

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

When I write a book, I want to be able to learn a lot of stuff, so I like the idea of endings because I can go from how we die to how the universe dies, and along the way learn a lot of biology and some of the subjects 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 of it. We, in our culture, have these difficult problems like the economy and whether our kids are going to get jobs, and whether the Earth is going to get too hot for us to live comfortably. In a sense, worrying about these big and dramatic endings, it's almost a relief.

Many of them are, of course, remote and not really a prospect that anyone has to really worry about day to day. It's not that they get gloomy or depressed by it, they just think: This is fascinating. The world could really end all these different ways. 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 of catastrophic scenarios do people seem to fear the most?

Impey: People are always going to ask questions 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 been any talk about asteroids or impacts, that is on peoples' minds, so I talk about that.

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

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

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

If [Jupiter's moon] Europa was a little hotter, then it would become a nice water world, and you could just build islands and live there, but it doesn't have a good atmosphere.

Terra-forming Mars is another thing that people have talked about ? what would it take to melt the ice on Mars and then feed the atmosphere with gas and small plant life to 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 do either.

Beyond the solar system, people are actually quite optimistic that Alpha Centauri, the nearest star, could have Earth-like planets. So, it's possible that the nearest Earth or Earth-like planet might be only 4 or 5 light-years away, which sounds good, but the cost and difficulty of getting a large number of people there is, of course, crazy. Our technology is completely inadequate.

It cost $50 billion 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 vast number of people light-years away, that's not even on the horizon of our technology. But of course, you're talking about a scenario that's millions of years away. If humans survive in any form, we'd presumably have much better technology by then.

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