Tonight is the season finale of Kyle XY on ABC Family at 8. It's all about the senior prom, which looks chock full of heartwarming, judging from the trailers I've seen. At the same time, this show about a superpowered teen mutant has done a really great job of keeping a sinister undercurrent lately, and Kyle's female counterpart Jessi just gets more and more entertainingly psycho. So if you haven't checked it out yet, you may want to grab your last chance tonight. After all, the episode will also teach us that looking forward to your prom too much will turn you gay:

Also, the History Channel has a new Modern Marvels, about whiskey, at 8 PM. (Not really very science fictional, but maybe the whiskey is sentient?) And then a new Cities of the Underworld at 9 PM.

And Encore is showing Mission To Mars at 9:45, just in case you want to relive Gary Sinise's life-changing encounter with a cheesy CGI alien.

Tuesday night has the next-to-last episode of Jericho season two, on ABC at 10 PM. Sadly, this is looking more and more like the next-to-last episode of Jericho, period, unless the Sci Fi Channel decides Jericho is a better investment than another season of Ghost Hunters. As you'd expect, Major Beck is not terribly happy about the drastic actions that Stanley took at the end of the previous episode, and he's not willing to blame everything on New Bern. Here are the first five minutes of the episode. (I apologize for the streaky video, this is the best source I could find.)

Also, the History Channel has a rerun of The Universe, all about the possibility of life on Mars.

And Encore has back-to-back Aliens and Waterworld, starting at 11:40 AM.

And at 2:10 AM Wednesday morning, Encore has Ultraviolet, the second-best movie featuring Gun-Kata. (The first being director Kurt Wimmer's Equilibrium, of course.)

Wednesday, the Discovery Channel has a new Futureweapons, "Hard Target." Subjects include new inflatable armor, shoulder-fired grenades, and the A-10 Thunderbolt II attack plane. Good times! And at 10, the History Channel has a new UFO Hunters, "UFO Gateways." The Hudson Valley in New York has hosted more than its fair share of UFO sightings — could this area be an interstellar gateway, used to travel across time and space, or even between dimensions? Another possible gateway area is Sedona, Arizona.

And at 10:10, Encore has Alien 3, while FX shows Batman Begins at 5, followed by The Core at 8 and 11.

Thursday there's a new Smallville on The CW at 8. Lionel Luthor has Clark abducted, and there's some crazy prophecy about how The Traveler will change the Earth for ever. But the main reason to watch this episode is to see just how crazy Chief Tyrol has gone since a certain revelation at the end of Battlestar Galactica season three. Here's a clip:

And then there's a new Lost, on ABC at 9, where we find out what Michael's been up to all this time. And Ben tries to convince Alex to flee the Others' camp before a coming assault. We posted a couple of preview clips the other day, and here's the episode's promo:

As for movies, at 12:15 Friday morning, AMC has The Thing

Friday is pretty slow, except for a bunch of Stargate reruns on Sci Fi. Also, at 1 PM, USA has Timecop, the greatest time-traveling Jean Claude Van Damme movie ever.

And at midnight, A&E has The Matrix, while Encore has 12 Monkeys. Try flipping back and forth between the two movies to create a single, crazy-paranoid narrative where nothing is real. And at 1:30 Saturday morning, TBS has Mars Attacks!, followed by Eight-Legged Freaks at 3:45.

Saturday morning, The CW has Legion of Superheroes followed by Spectacular Spider-man (featuring the debut of the Lizard), starting at 9:30.

And then at 9 PM, there's a new Torchwood on BBC America. It's Gwen's wedding day, but unfortunately, she's got a little surprise on the way. Zany wedding-pregnancy action, plus creepy monsters. You can read our recap of the episode here.

Sunday has the first hour of the broadcast premiere of Futurama: Bender's Big Score, in case you didn't already get the DVD. That's on Comedy Central at 8.

To some extent, it's understandable that space adventures play fast and loose with physics. After all, who wants to watch Han Solo spend years on the journey to Alderaan, only to find that the planet has twice Earth gravity and he can barely stand up, much less swagger?

The categories of mistakes in our report card should be pretty self-explanatory, but just in case, I'll expand on them a little bit:

• There's no sound in space
• Not all planets have Earth gravity
• Planets should have diverse climates, instead of one unified climate across a "desert planet" or "forest planet."
• It shouldn't be too easy to communicate with alien creatures, without some kind of high-technology "translator" explanation.
• And it definitely shouldn't be too easy for humans to interbreed with aliens.
• Humans exposed to vacuum without a spacesuit shouldn't explode or shatter. And a "hull breach" where the ship's crew is exposed to vacuum should kill everyone instantly.
• You can't have fires in space, unless there's oxygen leaking out somehow.
• Asteroids or other objects shouldn't be able to float close together without falling into each other's gravity
• People shouldn't be able to dodge lasers and other speed-of-light weapons
• And there's no reason why someone would move in slow-motion in zero gravity.
• Faster-than-light travel is probably not ever going to be possible.

First of all, here's a brief chronology of the Mars movie boom:

1999: Escape From Mars. A made-for-TV movie from UPN. Five astronauts journey to Mars in the second decade of the 21st century. They must deal with corporate greed and inferior computer components, plus their own demons.

2000: Red Planet. Okay, this one isn't quite as serious. Humanity stars seeding Mars with algae that's supposed to create a breathable atmosphere. But then the algae vanishes, and a team led by Carrie-Ann Moss goes to investigate. It turns out Mars now does have a breathable atmosphere, but it also has evil aliens and a killer robot.

2000: Mission To Mars. This may have been the most serious attempt to date at portraying the real conditions on Mars, based on the images that were available at the time. The first crewed mission to Mars gets lost, but there's one survivor. So Gary Sinise and pals rocket off to Mars, only to run into trouble as well. In the end, they enter a giant white mausoleum with breathable air, and the movie falls apart when they meet a cute alien who tells them that Martians seeded Earth with life:

2000: Mars And Beyond. An early Web series, on the Cyber Sci-Fi Network, Mars And Beyond was written by former Star Trek: The Next Generation producer Herbert Wright, also known as the "father of the Ferengi." (Not something I would brag about.) It's 2014, and a team of astronauts is sent to Mars. Officially, their mission is just to explore, but unofficially they're there to answer the question: "Are we alone?"

Ghosts of Mars (2001). I almost left this one out, because in some ways it's a throwback to the old pulpy Martian movies, and it depicts a Mars that's long been settled, like Total Recall and other earlier movies. Mars has been terraformed, and you can breathe the atmosphere without a spacesuit. At the same time, director John Carpenter did make an effort to depict a semi-realistic Mars, using tons and tons of red food dye to make the gypsum-mine location look Martian enough and trying to make the sets look as though the Martian winds had battered them. Plus he had a local holy man bless the set before filming. That has to count for something. Plus it has Reavers, before Joss Whedon put them in Firefly.

2002: Lost On Mars. This sounds pretty horrific, and I'm determined to hunt down a copy now. The first ever astronauts land on Mars, to investigate a strange energy reading. They discover that Mars once held intelligent life, and then they find a device that sends them spiraling back in time THREE BILLION YEARS to a barbarian empire that once ruled Mars. With, like, swords and things. They get captured by the movie's director, wearing a barbarian costume. And then it veers off into matriarchal Martian barbarian politics. Turns out there's a sequel, and they're both coming out on DVD soon.

2002: Stranded aka Náufragos. A Spanish movie, Stranded stars Vincent Gallo as a member of an expedition that crashes on Mars. It's shot in a documentary-like style and tries to depict the Martian landscape realistically. The humans discover the remains of an ancient Martian civilization, complete with an area that has breathable air. And they find out they can eat the ancient lichens on Mars, allowing them to survive until they can be rescued.

Where did the Mars-movie trend come from in the first place? The fact that NASA was prepping a much-publicized push to send orbiters and rovers to Mars may have helped inspire film-makers. (NASA also sent up some craft during the 90s, but they were lost on arrival. Also, as Moria points out, the 1990s was a high-water mark for Mars novels, including Kim Stanley Robinson's Red Mars trilogy and Greg Bear's Moving Mars. The development process for the Mars movies of 2000-2001 probably started in the mid-1990s.

So what ended the Mars movie fad? Well, the fact that it was a fad probably had something to do with it. Just like the asteroid-on-course-for-Earth movie fad, this one had to end. But the fact that more real data, and realistic images, were going to start coming back from Mars may have helped as well. The 9/11 attacks, and the start of the Afghanistan and Iraq wars, may have changed the focus of movies in development, away from exploration and towards war. (But that probably wouldn't have had an impact until a few years later.) There's also the fact that none of these movies did that well: Mission To Mars, grossing around $68 million in the U.S., may have been the biggest, but Red Planet only made $18 million as compared to its $75 million budget.

• 
  
• Richard Cook, designer of MSL, said that it's three times heavier than Spirit and Opportunity, the two rovers currently on Mars right now. It's powered by nuclear energy, designed to last 20 years, travel 10 km, and comes equipped with a laser for vaporizing rocks so it can do chemical and mineralogical analysis on them. "We call it the death ray," he confessed. Joked NASA Jet Propulsion Lab Director Charles Elachi, "In a few years people will be visiting Mars and see bullet holes all over the place [from the laser]."
  
• When Cook and his team were designing Spirit and Opportunity, they wanted to do what he called a "built to print," meaning to the specs on paper. They wanted to base it on the model they'd developed for Sojourner, the previous generation Martian rover. But immediately they figured out that wouldn't work, especially with the more-complicated MER rovers, since they still had to fit inside a small lander. "it's hard to take a rover and put it inside a tetrahedron," Cook said with a laugh, referring to the shape of the lander.
  
• The MSL rover, which will blast off next year, will be able to do experiments that tell us a lot more about Martian water sources. It can do gas chromatography mass spectrometry (GCMS). It has an onboard camera.
  
• Steve Squyres said he was disappointed when Spirit landed in Gusev Crater, which he hoped would be a lakebed. Instead, it was covered in a layer of lava rocks. "I believe the lakebed is there, but it's covered in lava," he said. Luckily, Spirit was able to make it to the Columbia Hills nearby to study a wide variety of rocks.
  
• Some of the rocks that Spirit studied show strong evidence of having been saturated by water, probably steam. Most likely, the hit that created the Gusev Crater shot a bunch of superhot rocks out to the Columbia Hills, and these melted ground water into steam.
  
• "When we talk about water on Mars, what we really mean is sulfuric acid," Squyres explained with a grin.
  
• There is absolutely no doubt that there has been water on Mars, Squyres said, but the fact is that the ratio of water to rocks has always been very low. One piece of compelling visual evidence he showed us was from a study of the sorts of patterns water leaves in soil over years of flowing on it. He compared images of a characteristic, smile-shaped pattern created by waters from the Colorado River with images from rocks on Mars. The smile shapes and sizes were nearly exactly the same.
  
• The rover Opportunity is currently at the Victoria Crater, where it is studying layers in the cliffs to learn more about the geological history of Mars. Some layers make it clear that water did at one point saturate the planet's surface. The walls of the crater are so steep that scientists have to pilot the rover based on satellite images taken by a recently-arrived spacecraft. He showed us images from the spacecraft, which are so high-resolution that you can see Opportunity and the shadow of its antenna at the edge of the crater.
  
• About the Victoria Crater mission, Squyres said, "It takes a lot of guts to drive an 8 hundred million dollar piece of equipment along the edge of a cliff on another planet."
  
• Andrew Knoll said that the real question isn't whether there has been water on Mars, because surely there has been. The question is whether that water is habitable for life as we know it.
  
• Unfortunately for people who want to meet alien life, the prognosis is not good. Chemical and mineral evidence suggests that water on the planet is so salty and acidic that it wouln't support any organisms we know. "Water on Mars would be challenging for life as we know it," he said.
  
• Knoll added that water could have flowed on Mars if it was extremely salty because salt lowers the freezing point of water. Or it could have flowed as a result of asteroid hits that temporarily melted ice.
  
• MSL will do more definitive mineral analysis to determine what the chemical composition of Martian water might have been (or might be).
  
• There has been a lot of debate over the Martian "gullies," structures that look like they were cut into the Martian surface with water. Squyres said, "Some were created during the last five years and look like they've been created by water. But all the ones we've looked at have slopes that suggest they were probably caused by avalanche not water."

When the space age ended, the alien age began. In the early 1990s, the Disney Corporation decided to close down its Mission to Mars ride, itself a direct descendant of the Rocket to the Moon attraction Werner von Braun had helped to design. In its place came Alien Encounter, in which an extraterrestrial stows away on a spaceship. This made things easier for Disney, as one executive admitted: "One way for an attraction to remain timeless is for it to be based in fantasy, rather than reality."

After we stopped sending people into space, it was easier to spin elaborate fantasies. We no longer had any narratives about actual space travel, with all its challenges, to compete with our magical interstellar ships, DeGroot argues.

[Dark Side of the Moon: The Magnificent Madness of the American Lunar Quest] NYU Press 2006