Artist’s illustration of the WFIRST spacecraft. Credits: NASA’s Goddard Space Flight Center
NASA is building the Wide Field Infrared Survey Telescope (WFIRST), a space telescope whose measurements will help illuminate the dark energy puzzle and unveil other mysteries of the universe.
According to NASA's Jet Propulsion Laboratory (JPL), exploring the nature of dark energy is one of the primary reasons for building WFIRST. With a better understanding of dark energy, mankind will have a better sense of the past and future evolution of the universe.
The telescope has a primary mirror that is 2.4 meters in diameter, the same size as Hubble's, but with a view 100 times greater than Hubble's.
WFIRST was the top-ranked large space mission in the 2010 Decadal Survey of Astronomy and Astrophysics, and is slated to launch in the mid-2020s.
WHAT IS DARK ENERGY
Scientists have discovered that dark energy makes up about 68 percent of the total energy content of the cosmos, but so far mankind know little about it.
According to NASA, one explanation for dark energy is that it is a property of space. Albert Einstein was the first person to realize that empty space is not nothing. This form of energy would cause the universe to expand faster and faster.
Another explanation for dark energy is that it is a new kind of dynamical energy fluid or field, something that fills all of space but something whose effect on the expansion of the universe is the opposite of that of matter and normal energy.
This mysterious pressure remained undiscovered for so long because it is so weak that gravity overpowers it on the scale of humans, planets and even the galaxy, according to JPL.
It is only on an intergalactic scale that dark energy becomes noticeable, acting like a sort of weak opposition to gravity, said JPL.
WFIRST TO ILLUMINATE DARK ENERGY
Previous missions have gathered some clues for dark energy, but have not yielded results that strongly favor one explanation over another.
The WFIRST mission will advance the exploration of the dark energy mystery by mapping how matter is structured and distributed throughout the cosmos, and also by measuring large numbers of distant supernovae.
The results will indicate how dark energy acts across the universe, and whether and how it has changed over cosmic history, said NASA.
According to JPL, three survey methods will be used by the mission to search for an explanation of dark energy.
The High Latitude Spectroscopic Survey will measure accurate distances and positions of millions of galaxies using a "standard ruler" technique. The High Latitude Imaging Survey will measure the shapes and distances of multitudes of galaxies and galaxy clusters.
Another survey will be conducted on one type of exploding star. By combining distances with brightness measurements, scientists will see how dark energy has evolved over time, providing a cross-check with the two high-latitude surveys.
"The WFIRST mission is unique in combining these three methods. It will lead to a very robust and rich interpretation of the effects of dark energy and will allow us to make a definite statement about the nature of dark energy," said Olivier Dore, a research scientist at JPL, and leader of the team planning the first two survey methods with WFIRST.
SHED LIGHT ON UNIVERSE'S FATE
Discovering how dark energy has affected the universe's expansion in the past will shed some light on how it will influence the expansion in the future, said JPL.
If it continues to accelerate the universe's expansion, mankind may be destined to experience a "Big Rip." In this scenario, dark energy would eventually become dominant over the fundamental forces, causing everything that is currently bound together - galaxies, planets, people - to break apart, said JPL.
Exploring dark energy will allow mankind to investigate, and possibly even foresee, the universe's fate. Enditem
