Triangles abound in the night sky. You can take any three stars and connect them to make a variety of triangles. Amateur astronomers often navigate to a deep sky object by creating instant triangles, squares and other figures to help them negotiate a busy star field. There are even two official triangular constellations: Triangulum and Triangulum Australe, the Southern Triangle.
Binocular vision may be characteristic of more advanced life forms, but I’m advocating we take the next step: trinocular vision. Trinocular refers to the three eyepieces used for viewing and photography in a trinocular microscope; for this article we use it in the spirit of fun.
Let’s take a look at a fresh new triangle in the heavens this month comprised of Mars, Saturn and Spica. These three apexes all shine brightly at 1st magnitude and span the southwestern sky at nightfall. As you’d expect, any triangle involving planets never remains the same thanks to their tireless orbiting of the sun. A month from tonight, the three will be gathered into a much more compact equilateral triangle (all three sides of equal length).
Mars is much closer to the Earth and sun and moves more rapidly across the sky while Saturn, nearly a billion miles distant, appears to barely move at all. Spica is so much farther than either planet and essentially stays put for thousands of human generations.
The Mars rover Opportunity completed its 3,000th Martian day this past Monday July 2. The milestone marks NASA’s more than 15 continuous years of robotic presence on the Red Planet starting with the Mars Pathfinder rover in 1997 and followed by the Mars Global Surveyor orbiter, Mars Odyssey orbiter and Opportunity, the last two of which are still in service. At the same time the agency released a brand new panorama of “Greeley Haven” on the rim of Endeavour Crater, where Opportunity spent its most recent winter. The crater’s interior can be seen in the lower right of the photo below the horizon.
817 separate photos taken taken between Dec. 21, 2011, and May 8, 2012 were used to create the image showing the terrain around the rover where it was stationery for four months. Sunlight isn’t strong enough during the Martian winter to fully power Opportunity’s solar panels, so mission controllers park it in a protected spot in low-power mode until the sun is high enough to give the rover its get-up-and-go.