Astronomy enthusiasts around the world are gearing up for Tuesday’s celestial show: the transit of Venus across the face of the Sun. The small black dot of Venus, silhouetted against the bright Sun, will be visible with safe solar telescopes and, to those with especially good vision, with the naked eye when protected by eclipse glasses.
What's inside a planet? What instruments do scientists use to figure it out? And what clues does a planet's surface give us? On Saturday, April 21, Lisa Walsh and I, scientists from the Museum's Center for Earth and Planetary Studies, invited visitors to the National Air and Space Museum's Explore the Universe Family Day to think about these questions, through two hands-on activities relating to our research into tectonics on Mercury.
We are all familiar with the climate on Earth: the seasons, the range of surface temperatures that are just right for being a water world, the oxygen we breathe, the ozone layer that protects us from UV radiation. In short: habitable. So what other bodies in the Solar System might be (or might have been) habitable, and why aren’t they today? Mars probably comes to mind, and for good reason. Mars has the most similar climate to our own, with water ice caps at the poles, seasonal snow, and dust storms. This is because Mars has a similar axial tilt as the Earth, which creates similar seasonal temperature variations.
If all goes according to plan, on November 25th the Mars Science Laboratory (MSL) rover Curiosity will leave the Earth and begin its journey to Mars. Any delays due to weather or other factors should be accommodated by a launch window that extends until December 18th. The spacecraft will use a new landing system to arrive at its landing site on Mars in August, 2012, and the rover carries an impressive array of scientific instruments.
The night opened with few clouds and a bright waxing gibbous moon. Alex and I, interns at the National Air and Space Museum, stood outside with Sean O'Brien, astronomy educator at the Museum and Albert Einstein Planetarium technician, to survey the sky and anticipate the night. This was my first star party at the Museum. As we set up, the first line of visitors formed outside the door of the Public Observatory waiting for 6 p.m. — opening time. We set up the Tele Vue telescope first. The view was spectacular. Along the terminator, the line between the dark and light sides of the Moon, craters popped between the stark white of the moon and the blue of the sky.
Here is a riddle: What takes more than 60 locations, 5 years, and 150 scientists to decide? The landing site for the Mars Science Laboratory (MSL) rover Curiosity. Picking the landing site for a spacecraft to land on another planet is always serious business. And the job of finding the best location for Curiosity to set down on Mars was no exception. Curiosity’s mission is geared towards understanding whether Mars could have ever been habitable.
Most people know that satellites in orbit do useful things such as collect images of the Earth's surface. At the National Air and Space Museum I use satellite images in my job to understand changes in the Earth's land surface.
Today at 8:45 pm EDT (March 18, 2011, 12:45 am UTC), MESSENGER will become the first spacecraft ever to enter Mercury's orbit. With MESSENGER on the last leg of its journey, I’m reminded how long it has taken to get there. I watched the spacecraft launch in the early morning hours of August 3, 2004, almost six and a half years ago. Now after one flyby of Earth, two flybys of Venus, and three flybys of Mercury, the spacecraft will catch up with Mercury again, but this time it will be captured by the planet. You might think as one of our closest neighbors in the Solar System it would take a lot less time to get into Mercury orbit – but because Mercury is the closest planet to the Sun, at a distance where the influence of the Sun’s gravity is much greater, it is a challenge to reach and orbit.