TODAY IN HISTORY: Planet Venus, Observed By NASA’s Pioneer 12 Space Probe On February 26, 1979.

Every Moon Landing of the 50s and 60s by designer Margot Trudell

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Venus is the second closest planet to the Sun and has the highest surface temperature of any planet in our solar system, with an orbital period of about 225 Earth days. Because of its similar gravity and size, it is sometimes known as Earth’s “sister planet.” However, besides these two aspects, the two planets have almost nothing in common. With the densest atmosphere on any terrestrial planet in the solar system, the surface pressure on Venus is about 92 times that of Earth; the same pressure one kilometer beneath Earth’s oceans.

Even though Venus is comparatively much further away from the Sun than Mercury, it is the hotter planet with a surface temperature of around 462 °C; this is because of its dense atmosphere of greenhouse gases such as carbon dioxide and sulfur dioxide. One remarkable aspect of the atmosphere of Venus is the precipitation of liquid sulfuric acid. The surface geology of the planet has been observed by NASA for over twenty years now, and it is seen that there is extensive and violent volcanism at the surface.

(image sources: NASA; http://www.the8planets.com/wp-content/gallery/planet-venus/venus-atmosphere.jpg, http://www.boskowan.com/blanensko/)

Please Build A Cloud City Over Venus 

Why Isn’t Our Universe Perfectly Smooth?

“This seems, at first glance, to pose a tremendous problem. If inflation stretches space to be flat, uniform, and smooth, indistinguishably so from perfection, then how did we arrive at a clumpy Universe today? Both Newton’s and Einstein’s theories of gravity are unstable against imperfections, meaning that if you start with an almost-but-not-quite perfectly smooth Universe, over time, the imperfections will grow and you’ll wind up with structure. But if you start with perfect smoothness, with literally no imperfections, you’re going to remain smooth forever. Yet this doesn’t jibe with the Universe we observe at all; it had to have been born with imperfections in its matter density.”

One of the great successes of cosmic inflation is to set up the initial conditions for the Big Bang that we knew we needed, including giving us a Universe that had the same temperature and density everywhere. But this couldn’t have been a perfect smoothness, otherwise we’d never have formed stars, galaxies, and the cosmic large-scale structure we observe today in the space we inhabit. So how did we come to be clumpy? The Universe must have been born with initial imperfections in them. If you treat inflation as a classical field, you’ll never get them that way, but if you recognize that it’s a quantum field, with the associated quantum fluctuations that we know must be there, the whole story changes. Not only does inflation give you these cosmic imperfections, but it gives you the full spectrum of them that you can then go check against observations.

These predictions were made in the early 1980s, and were verified decades later by COBE, WMAP, and Planck. It’s a huge victory for a great scientific theory!

Celebrities are already planning their trips to Mars, but should we head for Venus instead? 

Sequence of Venus atmosphere images taken by the Venus Monitoring Camera (VMC) during the Venus Express orbit in July 2007. The view shows the southern hemisphere of the planet.

Credit: ESA/MPS/DLR/IDA

When it landed on Venus on December 15th, 1970, Venera 7 became the first spacecraft to achieve a soft-landing on another planet. Only able to transmit surface data back to Earth for 23 minutes due to signal degradation, it was determined by Venera 7’s transmission that the atmosphere of Venus is composed 97% of carbon dioxide, with a temperature reading of 887°F (475°C).

'Sail-Rover' could make Venus exploration possible.

NASA’s Innovative Advanced Concepts program is funding a study into the possible use of a sail powered rover to explore the 500°C surface temperatures of Venus.

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Ten interesting facts about Uranus

Like the classical planets, Uranus is visible to the naked eye, but it was never recognised as a planet by ancient observers because of its dimness and slow orbit. Sir William Herschel announced its discovery on 13 March 1781, expanding the known boundaries of the Solar System for the first time in history and making Uranus the first planet discovered with a telescope.

1° Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. Uranus is similar in composition to Neptune, and both have different bulk chemical composition from that of the larger gas giants Jupiter and Saturn.

2° Like all of the giant planets, Uranus has its share of moons. At present, astronomers have confirmed the existence of 27 natural satellites. But for the most part, these moons are small and irregular.

3° Uranus’ moons are named after characters created by William Shakespeare and Alexander Pope. These include Oberon, Titania and Miranda.  All are frozen worlds with dark surfaces. Some are ice and rock mixtures.  The most interesting Uranian moon is Miranda; it has ice canyons, terraces, and other strange-looking surface areas.

4° Only one spacecraft in the history of spaceflight has ever made a close approach to Uranus. NASA’s Voyager 2 conducted its closest approach to  Uranus on January 24th, 1986, passing within 81,000 km of the cloud tops of Uranus. It took thousands of photographs of the gas/ice giant and its moons before speeding off towards its next target: Neptune.

5° Uranus has rings: All the gas and ice giants have their own ring systems, and Uranus’ is the second most dramatic set of rings in the Solar System.

6° Uranus makes one trip around the Sun every 84 Earth years. During some parts of its orbit one or the other of its poles point directly at the Sun and get about 42 years of direct sunlight. The rest of the time they are in darkness.

7° All of the planets in the Solar System rotate on their axis, with a tilt that’s similar to the Sun. In many cases, planet’s have an axial tilt, where one of their poles will be inclined slightly towards the Sun. But the axial tilt of Uranus is a staggering 98 degrees! In other words, the planet is rotating on its side.

8° Uranus is approximately 4 times the sizes of Earth and 63 times its volume.

9° Uranus is blue-green in color, the result of methane in its mostly hydrogen-helium atmosphere. The planet is often dubbed an ice giant, since 80 percent or more of its mass is made up of a fluid mix of water, methane, and ammonia ices.

10° Uranus hits the coldest temperatures of any planet. With minimum atmospheric temperature of -224°C Uranus is nearly coldest planet in the solar system. While Neptune doesn’t get as cold as Uranus it is on average colder. The upper atmosphere of Uranus is covered by a methane haze which hides the storms that take place in the cloud decks.

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Images credit: NASA

A Clockwork Rover for Venus

A good watch can take a beating and keep on ticking. With the right parts, can a rover do the same on a planet like Venus?

A concept inspired by clockwork computers and World War I tanks could one day help us find out. The design is being explored at NASA’s Jet Propulsion Laboratory in Pasadena, California.

The Automaton Rover for Extreme Environments (AREE) is funded for study by the NASA Innovative Advanced Concepts program. The program offers small grants to develop early stage technology, allowing engineers to work out their ideas.

AREE was first proposed in 2015 by Jonathan Sauder, a mechatronics engineer at JPL. He was inspired by mechanical computers, which use levers and gears to make calculations rather than electronics.

By avoiding electronics, a rover might be able to better explore Venus. The planet’s hellish atmosphere creates pressures that would crush most submarines. Its average surface temperature is 864 degrees Fahrenheit (462 degrees Celsius), high enough to melt lead.

Steampunk computing

Mechanical computers have been used throughout history, most often as mathematical tools like adding machines. The most famous might be Charles Babbage’s Difference Engine, a 19th century invention for calculating algebraic equations. The oldest known is the Antikythera mechanism, a device used by ancient Greeks to predict astronomical phenomena like eclipses.

Mechanical computers were also developed as works of art. For hundreds of years, clockwork mechanisms were used to create automatons for wealthy patrons. In the 1770s, a Swiss watchmaker named Pierre Jaquet-Droz created “The Writer,” an automaton that could be programmed to write any combination of letters.

Sauder said these analog technologies could help where electronics typically fail. In extreme environments like the surface of Venus, most electronics will melt in high temperatures or be corroded by sulfuric acid in the atmosphere.

“Venus is too inhospitable for kind of complex control systems you have on a Mars rover,” Sauder said. “But with a fully mechanical rover, you might be able to survive as long as a year.”

Wind turbines in the center of the rover would power these computers, allowing it to flip upside down and keep running. But the planet’s environment would offer plenty of challenges.

The extreme planet

No spacecraft has survived the Venusian surface for more than a couple hours.

Venus’ last visitors were the Soviet Venera and Vega landers. In the 1970s and 1980s, they sent back a handful of images that revealed a craggy, gas-choked world.

“When you think of something as extreme as Venus, you want to think really out there,” said Evan Hilgemann, a JPL engineer working on high temperature designs for AREE. “It’s an environment we don’t know much about beyond what we’ve seen in Soviet-era images.”

Sauder and Hilgemann are preparing to bake mechanical prototypes, allowing them to study how thermal expansion could affect their moving parts. Some components of the Soviet landers had actually been designed with this heat expansion in mind: their parts wouldn’t work properly until they were heated to Venusian temperatures.

Tank treads for Venus

AREE includes a number of other innovative design choices.

Mobility is one challenge, considering there are so many unknowns about the Venusian surface. Sauder’s original idea was inspired by the “Strandbeests” created by Dutch artist Theo Jansen. These spider-like structures have spindly legs that can carry their bulk across beaches, powered solely by wind.

Ultimately, they seemed too unstable for rocky terrain. Sauder started looking at World War I tank treads as an alternative. These were built to roll over trenches and craters.

Another problem will be communications. Without electronics, how would you transmit science data? Current plans are inspired by another age-old technology: Morse code.

An orbiting spacecraft could ping the rover using radar. The rover would have a radar target, which if shaped correctly, would act like “stealth technology in reverse,” Sauder said. Stealth planes have special shapes that disperse radar signals; Sauder is exploring how to shape these targets to brightly reflect signals instead. Adding a rotating shutter in front of the radar target would allow the rover to turn the bright, reflected spot on and off, communicating much like signal lamps on Navy ships.

Now in its second phase of NIAC development, the JPL team is selecting parts of the AREE concept to be refined and prototyped. Team members hope to flesh out a rover concept that will eventually be able to study the geology of Venus and perhaps drill a few samples.