Hubble space telescope
Launch Date
April 24, 1990
COUNTRY OF ORIGIN
United States of America
MISSION COST
$1.5 billion USD
MISSION DURATION
Up to 20 years
DISTANCE FROM EARTH
575 km
TYPE OF ORBIT
Near-circular low Earth orbit
OBJECTIVE
To take images from space that will help our understanding of galaxies and the birth of stars and distant objects.
Main CAMERA IMAGE RESOLUTION
16 megapixels (two charge-coupled devices at 2048x4096 pixels)
PRIMARY MIRROR DIAMETER
2.4 metres (94.5 inches)
Mass
11,110 kg (24,500 lb)
SIGNIFICANCE OF TELESCOPE SPECIFICS
Hubble space telescope
SIZE MATTERS: There's a significant size difference between the primary mirror size for the 1990 Hubble Space Telescope (left) and the upcoming 2018 James Webb Space Telescope (right) (Photo: NASA)
The bigger the telescope, the better its vision. The smaller the telescope, the easier it is to get into space. Hubble Space Telescope is the heaviest telescope of the three, but has the instruments necessary to take detailed visible-light images of distant objects. On the other hand, Kepler, the lightest telescope, travelled the farthest from Earth, but only has one instrument — a photometer that observes a sample of stars. The James Webb Space Telescope has the largest primary mirror, but is significantly lighter than its predecessor, the Hubble Space Telescope. Larger primary mirrors collect more light, can see deeper into space, and produce sharper images. James Webb Space Telescope's designers are working for the balance between size and weight.
MAJOR DISCOVERIES
• Helped refine estimates of the universe's age down to approximately 13.75 billion years.

• An inexplicable force called "dark energy" is accelerating the rate of the universe‚Äôs expansion.

• Supermassive black holes are most likely at the centres of most, if not all, large galaxies. This holds important implications for theories of galaxy formation and evolution.
Image Sample (Taken by the Hubble Space Telescope)
Starburst galaxy M82
Glowing hydrogen blasts from the central nucleus of a starburst galaxy called M82. The pale star-like objects are clusters of tens to hundreds of thousands of stars. (Photo: NASA)
Kepler photometer and spacecraft
Launch Date
March 7, 2009
COUNTRY OF ORIGIN
United States of America
MISSION COST
$600 million USD
MISSION DURATION
At least 3.5 years, extendable to at least 6 years
DISTANCE FROM EARTH
149,597,871 km
TYPE OF ORBIT
Earth-trailing heliocentric
OBJECTIVE
To monitor the brightness of selected stars as a way to discover Earth-like planets orbiting other Sun-like stars
Main CAMERA IMAGE RESOLUTION
95 megapixels (42 charge-coupled devices at 2200x1024 pixels)
PRIMARY MIRROR DIAMETER
1.4 metres (55-inches)
Mass
1,052 kg (2,320 lb)
SIGNIFICANCE OF TELESCOPE SPECIFICS
Hubble space telescope
SIZE MATTERS: There's a significant size difference between the primary mirror size for the 1990 Hubble Space Telescope (left) and the upcoming 2018 James Webb Space Telescope (right) (Photo: NASA)
The bigger the telescope, the better its vision. The smaller the telescope, the easier it is to get into space. Hubble Space Telescope is the heaviest telescope of the three, but has the instruments necessary to take detailed visible-light images of distant objects. On the other hand, Kepler, the lightest telescope, travelled the farthest from Earth, but only has one instrument — a photometer that observes a sample of stars. The James Webb Space Telescope has the largest primary mirror, but is significantly lighter than its predecessor, the Hubble Space Telescope. Larger primary mirrors collect more light, can see deeper into space, and produce sharper images. James Webb Space Telescope's designers are working for the balance between size and weight.
MAJOR DISCOVERIES
• Kepler-22b: An extrasolar planet two-and-a-half times the size of Earth, orbiting a sunlike star, within a "habitability zone" where liquid and life might exist.

• As of Feb. 27, 2012, Kepler has found 1,790 host stars, 2,326 planet candidates, and 105 confirmed planets. Of the 2,326 planet candidates, 207 are approximately Earth-size.
IMAGE SAMPLE (Taken by the KEPLER PHOTOMETER AND SPACECRAFT)
Star cluster NGC 6791
This image zooms into a small portion of Kepler's full field of view: An eight-billion-year-old cluster of stars called NGC 6791. (Photo: NASA)
James Webb Space Telescope
Launch Date
Expected to launch October 2018
COUNTRY OF ORIGIN
United States of America, in collaboration with European Space Agency, Canadian Space Agency and contributions from 15 other countries.
MISSION COST
$8.7 billion (estimated)
MISSION DURATION
5 to 10 years
DISTANCE FROM EARTH
1.5 million km
TYPE OF ORBIT
Halo orbit around L2, a point well beyond the moon's orbit around the Earth
OBJECTIVE
Successor to the Hubble Space Telescope, optimized to take infared observations and study the formation of the first stars and galaxies.
Main CAMERA IMAGE RESOLUTION
33 megapixels
PRIMARY MIRROR DIAMETER
6.5 metres (255.9 inches)
Mass
6,200 kg (14,000 lb)
SIGNIFICANCE OF TELESCOPE SPECIFICS
Hubble space telescope
SIZE MATTERS: There's a significant size difference between the primary mirror size for the 1990 Hubble Space Telescope (left) and the 2018 James Webb Space Telescope (right) (Photo: NASA)
The bigger the telescope, the better its vision. The smaller the telescope, the easier it is to get into space. Hubble Space Telescope is the heaviest telescope of the three, but has the instruments necessary to take detailed visible-light images of distant objects. On the other hand, Kepler, the lightest telescope, travelled the farthest from Earth, but only has one instrument — a photometer that observes a sample of stars. The James Webb Space Telescope has the largest primary mirror, but is significantly lighter than its predecessor, the Hubble Space Telescope. Larger primary mirrors collect more light, can see deeper into space, and produce sharper images. James Webb Space Telescope's designers are working for the balance between size and weight.
MAJOR DISCOVERIES
• Using infrared technologies, the James Webb Space Telescope will complement and extend the discoveries of the Hubble Space Telescope.

• With longer wavelengths, the James Webb Space Telescope can look inside dust clouds where stars and planetary systems are forming today.

• It can also look much closer to the beginning of time and hunt for the unobserved formation of the first galaxies.

Exploring the Hubble, Kepler and James Webb space telescopes.


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