NASA’s Spitzer Space Telescope Will Soon Retire. What Will Take Its Place?

On January 30, NASA programs to shut down its Spitzer Place Telescope, which has offered essential observations of the universe for the earlier 16 decades. Spitzer gave very important infrared data to researchers, and they are now on the lookout to other telescopes to fill the gaps.

Spitzer observes light in the infrared part of the spectrum, which is light at extended wavelengths than what our eyes see. In the in the vicinity of-infrared (wavelengths closest to obvious light), dust will become clear, allowing astronomers peek into star-forming regions of galaxies or examine cooler stars. At slightly extended wavelengths, infrared light can be utilized to examine planetary devices close to other stars and the disks that form them. At the longest infrared wavelengths, astronomers examine neat clouds of dust and fuel, and even peer into the hearts of galaxies wrapped in dusty clouds.

Released in 2003, Spitzer’s mission experienced two phases. Initially Spitzer’s instruments, cooled with liquid helium to –459 degrees Fahrenheit (–273 degrees Celsius), observed light with wavelengths from 3 to a hundred and sixty micrometers for the duration of its cold mission. In 2009, the telescope ran out of coolant, commencing its “warm” mission. Spitzer could no extended observe extended wavelengths but ongoing observing at limited wavelengths: 3.six and four.5 micrometers.

But Spitzer is not the only space telescope in procedure nowadays, and present and foreseeable future telescopes do have infrared-sensing abilities. Here’s what astronomers will have in their infrared toolbox once Spitzer has been shut down.


The Hubble Place Telescope is famously just one of astronomy’s greatest workhorse telescopes. It does have the skill to observe infrared light, but that capability is limited. Hubble can detect infrared light only between .eight and two.5 micrometers, which doesn’t overlap with Spitzer’s present or earlier abilities. So, whilst Hubble can undoubtedly enhance Spitzer and other infrared observations, it are unable to switch Spitzer’s skill to chart the infrared sky.


NASA’s Vast-field Infrared Study Explorer (Intelligent) space telescope observes the universe with a .four-meter mirror at wavelengths from 3.four to 22 micrometers. Deactivated in 2011, the telescope was reactivated in 2013 as NEOWISE. Now, it is utilized to observe in the vicinity of-Earth objects, these kinds of as asteroids and comets. The telescope continues to be a important asset to infrared astronomy, but it doesn’t glance over and above our possess solar process, focusing on science only near to property.

James Webb

The James Webb Place Telescope (JWST) is NASA’s next infrared space observatory. But JWST is nevertheless a minimal about a yr from its present planned start day of March 2021. JWST will observe from .six to 28 micrometers, which ranges from the yellow-gold conclusion of the obvious spectrum to what astronomers connect with the mid-infrared. That addresses the two wavelengths presently observed with Spitzer’s warm mission but doesn’t lengthen as deeply into the significantly infrared as Spitzer once could. (The definitions of mid- and significantly infrared can change, but most astronomers determine the significantly infrared as wavelengths between about 25 and 350 micrometers.)

That suggests whilst JWST can switch Spitzer for astronomers who observe, say, stellar nurseries, neat stars, exoplanets, and the disks close to youthful stars, it cannot totally switch Spitzer’s skill for the duration of its cold mission to observe quite cold dust or the centers of some galaxies.


NASA’s proposed Vast Subject Infrared Study Telescope (WFIRST) has been on and off the chopping block in modern decades. The telescope, if released as planned in the mid-2020s, will use a two.four-meter mirror to observe in the vicinity of-infrared light between .forty eight and two micrometers. That places it more in line with the wavelengths Hubble can see, and beneath Spitzer’s wavelength selection.

WFIRST’s true declare to fame is proper there in its name. It will have a extensive field of check out in a position to see a hundred instances more area of the sky than Hubble in a one shot, but with the similar impression high quality. That will dramatically improve the quantity of science it can do and whilst it will not glance at the similar wavelengths as Spitzer, its in the vicinity of-infrared selection is suited to several initiatives like those that depend up galaxies, supernovae, and exoplanets.

So, are infrared astronomers just out of luck? Soon after all, infrared astronomy is mainly impossible from the ground mainly because the drinking water in Earth’s environment blocks most infrared light. Which is why telescopes are released into space, where by they get a crystal clear check out.

SOFIA is an observatory aboard an plane. It can fly above most of the drinking water in Earth’s environment to observe infrared light.NASA/Jim Ross


But, it turns out, you really do not require to go all the way to space to see the universe in infrared. The Stratospheric Observatory For Infrared Astronomy (SOFIA) consists of a telescope mounted inside a modified Boeing 747SP plane that flies between 37,000 and forty five,000 toes (11,300 to thirteen,seven-hundred m). That places it above ninety nine per cent of the drinking water in Earth’s environment. SOFIA observes light between .35 and 655 micrometers, which addresses the full selection of Spitzer’s capability — both of those warm and cold — as very well as JWST’s and more.


SOFIA is an observatory aboard an plane. It can fly above most of the drinking water in Earth’s environment to observe infrared light. (Credit history: NASA/Jim Ross)

In all, SOFIA is the greatest prospect to switch Spitzer in its entirety. Even greater, SOFIA’s mirror is bigger than Spitzer’s (two.5 m as opposed to .85 m), so it can offer greater impression high quality in some cases than the retiring telescope. And SOFIA’s telescope can be repaired and upgraded as required, extending both of those its life time and its abilities.

But there are tradeoffs. SOFIA commonly will make ten-hour flights, but it have to nevertheless land for refueling and other servicing. Since of Earth’s rotation, it can only observe the similar region of sky for a highest of a number of several hours at a time. The plane also usually takes time to get from just one spot to a further and could not be in the proper spot to observe limited-lived activities. And lastly, SOFIA is above most — but not all — of Earth’s environment, so in some cases, observations are nevertheless limited by the levels above it.

The Spitzer Place Telescope is a truly distinctive and remarkable telescope that has helped astronomers uncover clues about substantially of our universe, from the initial stars and black holes to planets close to nearby stars. Despite the fact that observing the infrared sky devoid of Spitzer could glance slightly various in the foreseeable future, astronomers nevertheless have equipment to continue peering deep into the universe.