Universities love press releases. Any news story containing the name of an institution that gets even the least bit of (positive) media attention is highly prized by university public outreach departments. And if that story is sure to grasp media headlines (something like "Broccoli Found to Increase Cancer Risk," "Pretzels: Solution to World Hunger?" or "Newly Discovered Poisonous Sludge Worm Named After Famous Politician," to make up a few) will have the university PR folks banging down an office door. Press coverage means increased prestige which means increased money.
In an environment like this, shakey or bad science is often presented as proven fact because a paper is published on it. For this reason, many scientists naturally shy away from press releases.
It also doesn't help that the press often garbles the science. I remember reading an article several years ago that claimed a newly-discovered planet outside our Solar System was "45 million light-years away." That would be an astounding feat, as 45 million light years would put the planet well outside our local neighborhood of galaxies! The true number was 45 light years, which puts the new planet around a nearby star in our own Milky Way galaxy.
Yet press releases are important, because they are one of the few means to get new science in the public eye. We astronomers want you to know what we are up to, and what cool things we are finding across the Universe. But, often, what we announce in a press release is later found to be slightly (or greatly) incorrect. That is science. We can observe the universe and try and describe what we are seeing, only to later find that we mis-interpreted things. Or we make predictions based on a new theory, and those predictions are found to be wrong. And, sometimes we are right. But often we don't know for certain that we are right until many years down the road, and we want you to share in our excitement now.
I was thinking about these things this weekend when I read a couple of news stories on new science coming out of Mars. The first story talks about how Mars may not have as much water as we thought. But, wait, didn't we just read stories about Mars having LOTS of water? This is a story that, every few months, you see a new headline. Some scientists think Mars has a lot of water hidden under its surface, others disagree strongly. But, since we are talking about Mars and possible life on Mars, the PR firms are out in force, pushing scientists to make press releases on tentative evidence. And so, you get conflicting pictures in the press. The long and short of the story is this: there are features on Mars that some scientists think were caused by water and others think could have been caused by other things. Until we get a probe on the ground near these areas and find (or don't find) large lakes of ice under the surface, this controversy will rage on. So, the next time you see a headline about water (or lack thereof) on Mars, take it with a grain of salt.
The other story was about possible caves on Mars discovered from new pictures. And you may remember a similar story coming out several months ago on Martian caves being discovered (somewhere else). What is new about this story? Not too much -- more caves, and some discoveries on the temperatures of the caves (the temps are found to vary a lot, unlike caves on Earth). But, since caves might hold Martian life, it makes a good story! So, even though a similar story has been released previously, this one gets out, too.
The point of this is not to disparage the scientists working on these questions. Their work is important, and they want to share what they are doing. But once their science gets through the hype of public relations, the true new science is often the first casualty of the story. So, when you hear about a new scientific discovery on the news, whether in astronomy, physics, biology, or any other science, be a little sceptical. In time, the science may or may not hold up to scrutiny. This isn't to say you shouldn't believe a word of what you hear, but try to ferret out the grains of truth from the oceans of hype. It's not an easy task to do that, but that's one reason I'm here!