Consider for a moment this new image of M16 by the Hubble Space Telescope. This photo of M16 is taken in optical wavelengths. The kind of light you can see with your eyes (albeit enhanced). M16 is a star forming region meaning the gas inside the nebula is compressing into new stars. These new stars are forming deep inside the pillars, seen in the image as well as in the nebula in the background. Because of the nature of star formation, the dust surrounding these new stars is quite dense (after all it created a star). If the dust is so dense, how do we see these baby stars? One of the ways is Infrared Astronomy! IR and near IR radiation from these stars cuts through most of this dense dust and reveals itself to cameras tuned to its wavelength. IR radiation is emitted at a much longer wavelength than optical light, and thus is less affected by obscuring dust. By tuning into this radiation we can make the invisible visible.
Isn’t science great?! I created this image using two sets of Hubble data. The first is in optical light and the second is in IR and near IR.
By looking again in near IR light, we can see multitudes of previously invisible stars and details. Our galaxy is a dusty place, and with the help of infrared light, astronomers are lifting the veil and seeing the invisible. The birth of stars, exoplanets, and even traces of the Big Bang. Still don’t think infrared is important? NASA is spending $8.8 billion on a new space telescope, the successor to Hubble, called the James Webb Space Telescope. The JWST is specifically designed to operate in the near infrared and infrared range. It will launch in 2018.
One last great thing about infrared light is that you can use a “regular” telescope mirror to see it! All you need is a camera sensitive to its wavelengths. Many observatories such as the Keck Observatory on Mauna Kea (more on that in the next post), and the Hubble Space Telescope operate in both infrared and optical wavelengths.