Astronomers know of about 60 rocky exoplanets orbiting in the habitable zones of their stars. When they try to determine how habitable these planets might be, detecting water in their atmospheres plays a huge role. But what if there was another way of measuring the water content in these worlds?
Researchers are developing a way of modelling these worlds to determine how much water they have.
Whenever something happens with Betelgeuse, speculations about it exploding as a supernova proliferate. It would be cool if it did. We’re far enough away to suffer no consequences, so it’s fun to imagine the sky lighting up like that for months.
Now the red supergiant star has brightened by almost 50%, and that has the speculation ramping up again.
Indulge your inner man-child (or woman-child) with these LEGO versions of the Blue Origin Blue Moon lunar lander, New Glenn rocket, and launch tower. This new design is currently gathering supporters on the LEGO Ideas website. If it gets enough supporters, LEGO will review it and possibly build it.
Planet orbits are so easy to picture – eight nearly concentric hula hoops centered on the sun. Comets are weirder. Their orbits vary from tapered ellipses shaped like cigars to completely open-ended parabolas and even hyperbolas. Comet ISON’s highly-elongated (stretched out) orbit is best described as hyperbolic, although that’s subject to change if Jupiter gets into the act and gives the comet a gravitational nudge during its outbound journey. As the largest planet, it has a special knack for this kind of trick, having tamed many a wayward comet’s orbit into a neat ellipse.
Comets in hyperbolic and parabolic orbits are typically making their first trip to the sun from the bitterly cold and distant Oort Cloud, a roughly spherical volume of space beginning about 3,000 times Earth’s distance from the sun and extending outward to 50,000 times that distance or nearly one-quarter of the way to Alpha Centauri. The Cloud is believed to hold trillions of icy comets. Think of it as the sun’s ultimate beer cave.
To help visualize Comet ISON’s travels across the solar system we can always go the Internet and search for images and video, but sometimes it’s fun to use your own hands. Building a model using a simple cardboard template can make the knowledge “stick”. Not to mention it’s an excellent classroom activity for teachers preparing students for the comet’s post-perihelion display. All you need is this color pdf file, a printer and a few minutes to assemble.
Planets’ orbits are only slightly tilted to each other, but Oort Cloud comets drop in from any angle they choose. Gravitational interactions with passing stars and clouds of interstellar gas nudge them into the inner solar system, where they’re cooked by the sun into glowing and long tails composed of vaporizing ice and dust. Long ago, some passing star gave ISON a push. It’s been falling toward the sun ever since.
Animation of Comet ISON’s orbit created by NASA
While it may be tough to picture Comet ISON’s orbit slicing the planetary racetrack at a 62-degree angle, the paper model will give you an intuitive understanding of ISON’s path and comet orbits in general.
P.S. In case you’re a klutz with a scissors just click on the Youtube video above.