Mining Data From Stardust

Abundantly found in the stardust that makes up the cosmos, space diamonds consist of carbon just like those found on Earth, but they differ in size and importance.

These gemstones, commonly called nanodiamonds, are roughly 25,000 times smaller than a grain of sand. Unlike regular diamonds that hold great monetary value the bigger they are, the tiny nanodiamonds have a different value—in the form of knowledge. With the adage of knowledge being power, some could argue that they are therefore worth much, much more by opening up new ways to learn about the universe.

Nanodiamonds, just like all objects in the universe, emit light over the entire electromagnetic spectrum and scientists believe that by studying the properties of this light, they can better understand the origins of the universe and learn more about how it has developed and changed over time.

HOW ARE THEY EVEN SEEN?

Given the right tools, technology and atmospheric conditions, this light could be seen by scientists on Earth. However, since the Earth’s atmosphere tends to block out certain types of radiation, the best way to study nanodiamonds is by locating a telescope outside of the atmosphere.

Enter the Spitzer.

SUPER EYE IN THE SKY

The Spitzer Space Telescope, a super-sensitive instrument launched in 2003, is the fourth and final of NASA's Great Observatories, and is best known for having a high sensitivity to infrared radiation.

Spitzer was specifically designed to house a cryogenic telescope assembly since its detectors and telescope must be cooled to only about five degrees above absolute zero (-450 degrees Fahrenheit, or -268 degrees Celsius). 

When light from nearby stars hits the molecules that make up the nanodiamonds, energy is absorbed from infrared radiation and then excites the bonds in the molecules to a higher state of vibration. This causes the bonds to either bend, twist or stretch, resulting in distinctive wavelengths of infrared light being produced.

Spitzer’s super-sensitive infrared spectrometer then breaks that light into its component parts. Data collected is shown as an infrared spectrum, with the resulting image indicating wavelength patterns helping to identify what elements and molecules the object is made of, thus uniquely identifying the nanodiamonds based on their “infrared fingerprint.”

Considered a technological marvel, Spitzer includes many innovative features never used on previous space missions, yet the telescope’s fully functioning lifespan is limited. Its cooling system has been exhausted, allowing some components to overheat and not function. Still operable are the two shortest wavelength modules of the IRAC camera that will continue to be used, allowing further data discovery based on nanodiamond composition, but to a more limited degree.

NANODIAMOND DATA PROSPECTING

Recently astrochemists have focused their efforts on Elias 1, the Orion Bar, the CS region of HD 44179 and the Red Rectangle nebula where the unique infrared emission from nanodiamonds has helped identify the chemical form of interstellar matter. This provided new knowledge about the physical properties of celestial objects and their interactions over time and is helping scientists to better understand the universe.