Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. Your tax dollars help promote science! The following article was provided for reprinting by the Night Sky Network in March, 2020.
By David Prosper
Cancer the Crab is a dim constellation, yet it contains one of the most beautiful and easy-to-spot star clusters in our sky: the Beehive Cluster. Cancer also possesses one of the most studied exoplanets: the superhot super-Earth, 55 Cancri e.
Find Cancer’s dim stars by looking in between the brighter neighboring constellations of Gemini and Leo. Don’t get frustrated if you can’t find it at first, since Cancer isn’t easily visible from moderately light polluted areas. Once you find Cancer, look for its most famous deep-sky object: the Beehive Cluster! It’s a large open cluster of young stars, three times larger than our Moon in the sky. The Beehive is visible to unaided eyes under good sky conditions as a faint cloudy patch, but is stunning when viewed through binoculars or a wide-field telescope. It was one of the earliest deep-sky objects noticed by ancient astronomers, and so the Beehive has many other names, including Praesepe, Nubilum, M44, the Ghost, and Jishi qi. Take a look at it on a clear night through binoculars. Do these stars look like a hive of buzzing bees? Or do you see something else? There’s no wrong answer, since this large star cluster has intrigued imaginative observers for thousands of years.
55 Cancri is a nearby binary star system, about 41 light years from us and faintly visible under excellent dark sky conditions. The larger star is orbited by at least five planets including 55 Cancri e, (a.k.a. Janssen, named after one of the first telescope makers). Janssen is a “super-earth,” a large rocky world 8 times the mass of our Earth, and orbits its star every 18 hours, giving it one of the shortest years of all known planets! Janssen was the first exoplanet to have its atmosphere successfully analyzed. Both the Hubble and recently-retired Spitzer space telescopes confirmed that the hot world is enveloped by an atmosphere of helium and hydrogen with traces of hydrogen cyanide: not a likely place to find life, especially since the surface is probably scorching hot rock. The NASA Exoplanet Catalog has more details about this and many other exoplanets at bit.ly/nasa55cancrie.
How do astronomers find planets around other star systems? The Night Sky Network’s “How We Find Planets” activity helps demonstrate both the transit and wobble methods of exoplanet detection: bit.ly/findplanets. Notably, 55 Cancri e was discovered via the wobble method in 2004, and then the transit method confirmed the planet’s orbital period in 2011!
Want to learn more about exoplanets? Get the latest NASA news about worlds beyond our solar system at nasa.gov.
The Night Sky Network program supports astronomy clubs across the USA dedicated to astronomy outreach. Visit nightsky.jpl.nasa.gov to find local clubs, events, and more!
Observations from NASA’s Spitzer Space Telescope have led to the first temperature map of a super-Earth planet — a rocky planet nearly two times as big as ours. The map reveals extreme temperature swings from one side of the planet to the other, and hints that a possible reason for this is the presence of lava flows.
The first human-rated expandable structure that may help inform the design of deep space habitats is set to be installed to the International Space Station Saturday, April 16. NASA Television coverage of the installation will begin at 5:30 a.m. EDT.
NASA has selected Aerojet Rocketdyne, Inc. of Redmond, Washington, to design and develop an advanced electric propulsion system that will significantly advance the nation’s commercial space capabilities, and enable deep space exploration missions, including the robotic portion of NASA’s Asteroid Redirect Mission (ARM) and its Journey to Mars.
NASA will host a news teleconference at 1 p.m. EDT Tuesday, May 10 to announce the latest discoveries made by its planet-hunting mission, the Kepler Space Telescope.
