Little Mercury puts on a nice early morning show during the first three weeks of January. Look for it about an hour before sunrise, low in the southeast. It will appear far to the lower left of much brighter Venus.
Venus appears as the brilliant "Morning Star" this month. It rises in the southeast predawn sky shortly after 4 a.m. On Jan. 29 and 30, the waning crescent moon will shine close to Venus before sunrise.
Mars is behind the sun, in relation to the Earth, and cannot be viewed this month.
The JWST’s primary mirror will consist of 18 beryllium segments, each 1.5 m in diameter. These gold coated mirrors will be precisely aligned and controlled so that they function as a single large mirror.
This is a composite image of two colliding galaxies, taken by the Hubble Space Telescope, the Chandra X-ray Telescope, and the Spitzer Space Telescope. The collision began over 100 million years ago and is still taking place 62 million light years from Earth.
The James Webb Telescope will be in a distant orbit where the sun, Earth and moon are in basically the same direction, so that their light can be blocked by a large shield. The extremely cold and stable temperature found there will enable very sensitive infrared observations.
Although the mirror in the Hubble Space Telescope is 15 times smaller than large Earth-based telescopes, it can resolve finer details of remote objects. It orbits the Earth at an altitude of 347 miles.
By orbiting close to the L2 point, the JWST will stay aligned with the Earth and sun as they both orbit the sun. This alignment will continue because both orbiting bodies will maintain a balance between gravitational pull and forward speed.
Mighty Jupiter shines brightly in the southwestern evening sky, setting before midnight. On the evenings of Jan. 9 and 10, the waxing crescent moon will wander close to Jupiter. Early in the month, use binoculars or a small telescope to view the blue-green disk of the planet Uranus, positioned just above Jupiter. This will be your best chance to locate Uranus all year.
Beautiful Saturn rises in the east shortly after midnight. For the best telescopic view of the magnificent ring system, wait until early dawn, when Saturn will be high in the southern sky.
Beyond the Hubble Space Telescope
"Science is the one human activity that is truly progressive. The body of positive knowledge is transmitted from generation to generation."
Edwin Powell Hubble
Our Earth's turbulent atmosphere interferes dramatically with our observations of the universe that totally surrounds us. It blocks out a broad range of the electromagnetic spectrum but allows a narrow band of visible light to reach the ground. That is why our eyes evolved to detect only the visible light. Besides absorbing most of the radiation from objects in deep space, the constantly moving cells of air above our heads create blurring in the images that astronomers take from the surface of the Earth.
In order to obtain extremely sharp images without blurring and to detect all of the various wavelengths of radiation that are blocked by our atmosphere, astronomers knew that they had to place their telescopes and detectors in orbit, above the Earth's atmosphere. Orbiting space telescopes such as the Hubble Space Telescope, the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope have greatly increased our knowledge of the universe and have provided us with incredibly gorgeous images of distant galaxies and nebulae.
Way back in 1989, astronomers began discussing a successor to the HST. They realized that any succeeding space telescope should be optimized to detect infrared (IR) radiation, instead of visible light, in order to study longer wavelengths and higher redshifts. These early discussions, many years ago, led to the development of the James Webb Space Telescope, which is currently in the construction phase.
The JWST will differ quite a bit from the HST. Hubble has a 2.4m main mirror but the JWST will have a 6.6m mirror, allowing for much better light gathering capabilities. Since there is no rocket large enough to accommodate a one-piece mirror that large, the JWST mirror will consist of 18 hexagonal mirror assembly segments which will be folded up to fit inside the launch vehicle and then unfolded after launch. While the Hubble is in a low Earth orbit 347 miles high and must shut down while in sunlight, the JWST will be located at the second Earth-Sun Lagrange point, called L2. This is a unique spot where the sun's gravity and the Earth's gravity combined allow the spacecraft to keep up with the Earth as it orbits the sun. Parking the spacecraft in a tight orbit around the L2 point will ensure that its shielding, the size of a tennis court, will be able to protect it from light and heat from the sun, Earth, and moon. No matter where the Earth is located in its annual path around the sun, the JWST will be positioned nearly a million miles above the night side of the planet, always ensuring a clear, unobstructed view of the cosmos. However, there could be a major problem with locating the spacecraft almost a million miles from Earth. Service calls to repair any faulty equipment will be impossible.
During the first stages of designing the JWST, astronomers set four main science goals for this revolutionary infrared telescope. They wanted to use this instrument to study:
The First Light goal involves locating and studying the predicted objects that were the first to emit light. The Assembly of Galaxies goal involves the precise imaging and spectroscopy of galaxies back in time to their earliest precursors so that we can better understand their evolution. The Birth of Stars and Protoplanetary Systems goal will hopefully unravel the secrets of the birth of stars and their evolution, including the formation of planetary systems. The Planetary Systems and the Origins of Life goal will attempt to determine the physical and chemical properties of planetary systems and investigate their potential for supporting life.
The public has become accustomed to viewing many of the beautiful cosmic images that Hubble has taken over the years and those taken by the JWST will be just as stunning. While Hubble's main imaging camera has 16 million pixels, the JWST's images will contain 32 million pixels in each image. Although these images will be taken in infrared wavelengths, computers will be able to transform them into visible light pictures. Infrared is one of several types of "light" that make up the electromagnetic spectrum. Its wavelengths are longer than visible light and our eyes cannot detect it. However, the JWST's instruments will be sensitive to both the near-infrared and mid-infrared radiation as long as they are kept below -370 degrees F.
Although NASA is the prime contractor of the JWST, both the European and the Canadian space agencies are contributing major components, while another 12 countries are playing some part in its development. The technology involved in this massive project is quite impressive. Both the Hubble and the JWST could detect an object the size of a soccer ball at a distance of 340 miles. However, the infrared capability of the JWST will allow it to track down objects that are 10-100 times fainter than Hubble can, allowing astronomers to penetrate ever deeper into space.
The JWST is scheduled to be launched from French Guiana in South America sometime in 2014 on an Ariane 5 ECA rocket. It will carry sufficient fuel for a 10-year lifetime. If all goes well, this incredible instrument will add greatly to our understanding of the universe that surrounds us.