Big Head Todd Wakeup Call And Spitzer’s Sunflower

Big Head Todd and the Monsters perform “Blue Sky” live in Mission Control this morning for the Discovery shuttle crew. This was the first time a crew has ever been awakened by a live band

Just a reminder. Unless the weather’s bad for the Wednesday landing of the space shuttle Discovery, tonight will be the last night we’ll get to see it in orbit before it returns to Earth. Some time later, the ship will be moved to the Smithsonian for display. You can watch it and the space station together in the sky twice this evening – at least in the Duluth, Minn. region

The first pass begins only 15 minutes after sunset at 6:20 p.m. CST. Both craft will cruise almost directly overhead and should be easy to see despite the bright sky. Discovery will fly by first, followed about two minutes later by the space station.  Which one will appear brighter? Likely the space station, but because of lighting angles, Discovery might briefly outshine the ISS.

A second, shorter-duration double flyby happens beginning at 7:56 p.m. very low in the southwestern sky. That one will be more difficult to see unless your view in that direction is ideal.

The various spiral arm segments of the Sunflower galaxy, also known as Messier 63, show up vividly in this image taken in infrared light by the Spitzer Space Telescope. The short slash at right is a distant background galaxy. Compare the labeled dust arms with their appearance in regular, visual light below. Click images to see larger, unlabeled versions. Credit: NASA/JPL-Caltech

NASA’s Spitzer Space Telescope, which can see beyond the color red and into the infrared part of the spectrum, recently photographed the Sunflower Galaxy, also known as M63 in Charles Messier’s catalog of deep sky objects. At 100,000 light years across, the galaxy is about the same size as our own Milky Way, and lies at a distance of 37 million light years. A small telescope shows it as a bright, fuzzy disk in the little constellation of Canes Venatici the Hunting Dogs.

M63 photographed in visual light. Here the dust lanes, marked A,B and C, appear dark in silhouette against pale clouds of stars too faint and distant to resolve individually. The pink areas are concentrations of glowing nebulae and newborn stars. I've tipped the photo for easy comparison to the Spitzer image. Credit: Jim Misti

Infrared light is not visible to the human eye. Instead we sense it as warmth through our skin. Spitzer is optimized to gather and photograph infrared light, which makes it ideal for studying dust warmed by stars in the spiral arms of galaxies like the Sunflower.

The Sunflower Galaxy (M63) is located in the stick-like constellation Canes Venatici right across from the Dipper's Handle. This map shows the northeastern sky around 8 o'clock local time. Created with Stellarium

In visual light, galactic dust looks like dark stripes or lanes of material cutting through the galaxy’s disk. Visual light can’t penetrate dust, so it appear in silhouette, blocking the view of background star clouds in the galaxy.

Compare the Spitzer photo of dust lanes A,B and C to the same one in Jim Misti’s photo. They’re like negative images of each other!

I shot photos last week of a home energy audit, where a technician used a hand-held infrared camera to scan a home for cold spots from outside air. The images were colored similarly to those taken by Spitzer. Red and oranges indicated warmth; blue and purple cold. Everyone there seemed to have a nice, healthy glow.

Infrared light lets us see into dust clouds where stars are being born as well as spot asteroids and comets too faint to be seen visually. It cooks our food on the stove and keeps us warm around the fire. It’s my favorite part of the spectrum from November through April.