With the launch of Sputnik in 1957, the Soviet Union kicked off the Space Race and for the first several years (arguable up until the Moon landing in ‘69), they dominated the United States. One of their “firsts” in the early years was taking the first photo of the dark side of the Moon 60 years ago this month.
Astronomer Kevin Hainline wrote a fascinating account of how the Soviet’s Luna 3 spacecraft took the photo and then transmitted it back to Earth.
First off, Luna 3, the first three-axis stabilized spacecraft, had to reach the Moon to take the pictures, and it had to use a little photocell to orient towards the Moon so that now, while stabilized, it could take the pictures. Which it did. On PHOTOGRAPHIC FILM.
And it gets WILDER because these photos were then moved to a little CHEMICAL PLANT to DEVELOP AND DRY THEM. That’s right, Luna 3 had a little 1 Hour Photo inside. Now you’re thinking, well, how do you get those actual photos back to the Earth?
How indeed? The spacecraft faxed the photos to Earth. A few years later, when the Soviets’ Luna 9 took the first photo on the Moon’s surface and went to transmit it back to Earth, a group in the UK was able to read the signal with a fax machine and the resulting image was published the next day on the front page of the Daily Express.
A vintage NASA-commissioned Rick Guidice painting gives a cutaway view of the inside of a space colony design known as the Stanford torus, a proposed habitat that would house 10,000 to 140,000 permanent residents. The rotating, doughnut-shaped ring could have a diameter of around 2 kilometers, revolving once per minute to give about 1.0g of artificial gravity on the inside of the ring through centripetal force. A massive system of mirrors would provide the sunlight needed for daily activity, agriculture, and so forth. (NASA Ames Research Center)
Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.
This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.
Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.
All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.
In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.
Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.
For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.
The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.
The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.
The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.
Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer.
How Did the Spitzer Space Telescope Detect this System?
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system.
Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.
The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.
At 40 light-years away, humans won’t be visiting this system in person anytime soon…that said…this poster can help us imagine what it would be like:
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Three moons of Jupiter : Ganymede, Callisto and Io. Credits : NASA/JPL.
latest Pluto images released Sept 10, 2015 by NASA. Second to last is Pluto’s moon Charon. Last is the original “up close” image of Pluto. Images taken by NASA’s New Horizons Spacecraft.
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Enceladus, moon of Saturn, observed by the Cassini space probe on December 19, 2015. (NASA)
Europe - André Kuipers
I - ISS Over Europe
II - Wolgograd
III - London
IV - Amsterdam
V - Naples
VI - Paris
(Original Photo credit to NASA)
International Space Station flyover
Happy Earth Day