Since its launch twenty years ago, the Hubble telescope has led a revolution in astrophysics. It has captured thousands of astounding images, seen the oldest known galaxies in the Universe, helped in our understanding of quasars and gamma-ray bursts, and played a hand in measuring dark energy. However, twenty years is a long time in technological terms and, after two decades and five servicing missions, Hubble is approaching the end of its useful life. While discussions are ongoing as to the eventual fate of the historical telescope, there are several more exciting and intriguing missions that NASA and ESA are planning for the next few years. These missions have the potential to astound astronomers more than Hubble, and to uncover some of the darker secrets of our universe.
Launch date: 2012
Target: Origin of the Milky Way
The main goal of Gaia is to provide answers concerning the very formation and evolution of our home galaxy — the Milky Way. Over a five-year mission, it will map more than a thousand million stars in three dimensions, creating a never-seen-before impression of the system. At the heart of the craft will be two visible-light telescopes working in unison to collect precise data on the positions of the stars, and splitting their light into different spectrums. Gaia will rotate slowly as it orbits at the L2 point 1.5 million km away, allowing the entire celestial sphere of our galaxy to be observed. Each object will be measured around 70 times, enough to trace any minute movements through space.
As well as providing a 3D map of the Milky Way, Gaia is expected to discover hundreds of new deep-space objects, everything from extra-solar planetary systems to asteroids within our own solar system; detailed orbits and masses of new planets will be measured, while many new comets will be discovered. Gaia will also measure the bending of starlight caused by the Sun’s gravitational field, and thus observe Einstein’s Theory of Relativity in full, glorious motion. The very structure of space-time will be scrutinised.
Name: Terrestrial Planet Finder
Launch date: 2014 / 2019
Target: Habitable planets
While the close viewing of extraterrestrial planets is currently beyond our technology, the TPF project’s goal is to detect planets most suitable to harbouring life. The effects of even the most basic life forms should be observable on a global scale, and the TPF aims to find signs of life by measuring the light spectrum of potentially life-spawning planets.
The mission will consist mainly of two parts: TPF Coronagraph with a planned launch in 2014, and TPF Interferometer around five years later. The TPF-C’s aim is to suppress the light of the central star of around 150 systems and search for terrestrial planets. The TPF-I will operate in mid-infrared, surveying around 500 stars for nearby terrestrial planets.
The mission will also provide valuable data on the formation of individual planets, as well as allowing accurate estimates on how often Earth-like planets are likely to occur. The realisation that Earth-like planets are much more common than we think would be absolutely astounding.
Name: Dark Energy Space Telescope
Agency: NASA / ESA
Launch date: TBA
Target: Dark energy
“Not knowing the nature of dark energy would be akin to an alien scientist trying to understand Earth’s surface without knowing the nature of water.” — Goddard Space Flight Centre
Dark Energy is perhaps the most intriguing scientific discovery of recent times, basically because nobody knows what it is. After Einstein introduced the Cosmological Constant in order to describe what was then thought to be a static Universe, he later reverted and described it as his “biggest blunder” when the Universe was found to be anything but static. However, the recent discovery has been made that the Universe is actually accelerating. Dark energy — a force not even Einstein could comprehend — is behind this phenomenon. Whatever it is, it’s strong enough to repel the effects of gravity, and makes up a staggering 70% of our Universe.
NASA and ESA aim to launch a dedicated mission to provide answers. Using an orbiting observatory with a telescope, the expansion history of the Universe and the very nature of dark energy will be probed over a six-year period. If successful, the resolution of the dark energy problem could have profound effects on the future study of matter, space, and time. The mission has the potential to completely alter the way we see our Universe.
Name: James Webb Space Telescope
Agency: NASA / ESA / CSA
Launch date: 2014
Earmarked as the successor to Hubble, the aim of the JWST mission is to be the premier observatory for the decade after launch. Defined by four main goals — the birth of the Universe, the formation of galaxies, the birth of stars and planetary systems, and the origins of life — it will study everything from the moments just after the Big Bang to the formation of galaxies and planetary systems, including the evolution of our own solar system. Using an IR telescope and a series of mirrors 6.5 metres in diameter, the JWST will orbit 1.5 million km away, at the L2 point, allowing it to see deeper into the cosmos than ever before. Where Hubble uses mainly visible light, the James Webb will be able to peer through clouds of stellar gas using the IR spectrum, while a sunshield the size of a tennis court will help keep the delicate observing equipment cool, which is vital for an IR telescope. It seems as though the James Webb will fill the sizable gap left by Hubble, and then some.
These missions provide the vanguard of a brand new era in space exploration. While Hubble has earned its place in history, these missions have the potential to make new history — whether through the discovery of hundreds of Earth-like planets, the explanation of the evolution of the Milky Way, or finally nailing the enigma of dark energy, the way we view our Universe is about to change forever. Both for professional astronomers and part-time stargazers alike, that is a thrilling prospect.
This article was supplied by Blair Martin from Constant Content.
Somewhat related article: The Search for Extraterrestrial Intelligence