While astronomical and cosmological knowledge of the universe has grown by leaps and bounds in the past few decades, some details remain beyond the grasp of current space- and ground-based telescopes — but not for long.
Two space telescopes, Herschel and Planck, are set to be launched in tandem by the European Space Agency (ESA) on May 14. They will peer deeper into space and time than any telescope in history.
NASA gets most of the attention when it comes to space telescopes, with the Hubble Space Telescope leading the way (Hubble is however a joint project with ESA). But that could soon change.
The observations made by these two European observatories could revolutionize our understanding of our universe, and answer some "basic questions about our place in the universe," said Paul Goldsmith, the NASA project scientist for Herschel at the Jet Propulsion Laboratory in Pasadena, Calif., which provided some of the key technology for the telescopes.
Herschel will be the largest, most powerful infrared telescope ever launched into space, and its observations in the far-infrared to sub-millimeter wavelengths of light will allow astronomers to study some of the coldest objects in space, not visible in other wavelengths.
Probing the universe
Herschel will look for the signature of water in comets in our own solar system, as well as in the interstellar gas and dust clouds that give rise to stars and planets.
When Herschel peers into those clouds, it will also be looking into the womb of star formation and should be able to see the formation of proto-stars for the first time.
The telescope will also look back in time to get the first good glimpse at the intense star formation early in the universe's history in young galaxies that shine brightly in the infrared.
"Herschel's going to really end up rewriting the books on how stars form," Goldsmith said.
Meanwhile, Planck will be looking in the microwave part of the spectrum, mapping the fossil light of the universe, the Cosmic Microwave Background (CMB) that is the relic radiation of the Big Bang, and learning more about the universe in its infancy.
Planck will be able to look at fluctuations in the CMB in more detail than ever before, which will tell astronomers more about how the large-scale structures of the universe — from galaxies to large voids — formed and evolved.
"Planck will provide the most precise data on the early Universe ever. We have never been so close to the Big Bang," said Rashid Sunyaev, director of the Max Planck Institute for Astrophysics in German, which provided some of the software for Planck.
Planck will also turn its eye on two of the universe's most mysterious quantities: dark matter and dark energy.
The telescopes will be sent into space aboard an Ariane 5 ECA launcher from the Guiana Space Centre in Kourou, French Guiana.
They will make their observations from the L2 Lagrangian point of the sun-Earth system — a gravitational stability point in space about 1 million miles (1.5 million kilometers) from Earth in the opposite direction of the sun — freeing the instrumentation from the interfering radiation of the sun, Earth and moon.
It will be two months before Planck and Herschel reach their final destination, and once they do, all their systems will have to be checked out before astronomers can start probing the heavens. Goldsmith estimates that the first observations will come in October.
Herschel and Planck won't last forever — they are slated for 3.5-year and 15-month missions, respectively. There is some possibility of extending those missions, but ultimately the helium that cools their instruments will run out.
But even without an extension, each mission promises to enhance our understanding of the universe we live in, and right now, astronomers are "waiting eagerly for things to get going," Goldsmith said.