http://marsrovers.jpl.nasa.gov/spotlight/spirit/a10_20040120.html
The Sky Is The Limit Jet Propulsion Laboratory January 20, 2004 Believe it or not, some of the scientists on the Mars Exploration Rover Science team don't really care too much about rocks - or for that matter anything on the surface of Mars. They have "higher" ambitions. Their passion lies in the skies - the martian skies - and, from the hazy glow of the atmosphere, they pull precious pieces of information. Two of these sky gazers are Mike Wolff and Mike Smith. They are brimming with energy because, in the next few sols, Spirit will be doing more atmospheric study than she's done since landing. "It's a bit of a running joke that the atmospheric team gets left out," laughs the jovial pair. "Let's be honest, this is predominantly a geology mission - water and rocks." The atmospheric team is also a little outnumbered, "There are very few of us atmospheric scientists who want to spend Spirit's time looking at the sky. The vast majority of the team wants to look at the ground." All the joking aside, Mike and Mike know the importance of good atmospheric data, explaining that it is crucial for "ground-lookers" to know what they are seeing. For instance, scientists study the light that is reflected from each surface to determine what minerals are in the rocks on Mars. In order to make accurate calculations, they must understand the atmosphere through which the light traveled before reaching the rocks and reflecting back. "They DO need us," smiles Wolff. "Our team provides information about the amount of dust and water vapor in the atmosphere, allowing other teams to make sense of what they're seeing." Beyond a supportive role, the atmospheric team is trying to answer big questions about the climate on Mars that will help all future Mars exploration. "We need a complete understanding of the environment we're working with - what conditions do we need to prep for? How much dust is there, and will it interfere with machinery? What are the temperature extremes that can interfere with the successful operation of instruments? The more we understand the weather on Mars, the more likely it is that a Mars mission will have success," explains Smith in a serious moment. The term "weather on Mars" can mean a lot of different things, but the atmospheric team is harvesting hypotheses from four main elements: air temperature, water-ice clouds, water vapor, and dust. Air Temperature Using the Mini-TES instrument, the atmospheric team can determine the temperature of the Martian atmosphere at various heights from the surface to about two kilometers (about 1.2 miles) above the surface. Orbiters and previous landed missions could not provide this near-surface information as precisely as Mini-TES can, and both Mikes are excited to have it. "All the major weather systems on Mars are affected by this lower area, so it's really fantastic to be seeing this detailed data," says Smith. These temperature readings assist engineers as they assess the rovers' heath. Engineers need to know if things are heating up on Mars so that they can prepare to keep the rover cool. Water Vapor "Water-vapor is a fancy atmospheric term for humidity," jokes Wolff. "If you've ever been in the south in the summer, you know what water vapor is." Mars does have some water vapor, but not much. In fact, Earth has about 10,000 times more water in its atmosphere than Mars does. The amount of water vapor in the atmosphere is important to scientists because it is a key part of the current climate and potentially gives clues about the distribution of water under the surface. Water-Ice Clouds Like the high, wispy, cirrus clouds we see here on earth, water vapor in Mars' atmosphere freezes and forms into cirrus-like clouds on Mars. By studying the quantity, location, and longevity of these clouds, scientists can better understand how water is exchanged between the martian surface and atmosphere. While orbiters have provided us with many great images of cloud-cover on Mars, they are limited by the time of day of their orbit and can only reveal what the clouds look like in a particular spot at a particular time. "With Spirit and Opportunity we can watch the clouds throughout the day and monitor how they change," explains Wolff. Dust Scientists operating a rover on the surface of Mars have one major concern when it comes to dust: accumulation. The planet is covered in the fine, powder-like material and daily winds blow it across the planet forming dunes and ripples. Too much of this dust on the solar panels could cause them to work less efficiently. The atmospheric team monitors how much dust is in the atmosphere and helps the engineering team evaluate the performance of Spirit's solar panels. During the mission, Spirit will point its Panoramic camera and Mini-TES instruments towards the sky, giving the atmospheric team another chance to shine. Most of the atmospheric sequences only take under 20 minutes, and are easy to fit into all the rover's other daily activities. "We'll hopefully have lots of these "fill-in" sequences throughout the mission," explains a smiling Smith. "We don't ask for much, but we promise to deliver a lot!" ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
