Category Science

When we speak about the space race between the U.S. and the Soviet Union that took place in the second half of the 20th Century, we often focus on the moon missions. There were, however, various other missions during this time that had many different objectives as well. One of these was the Venera programme that corresponded to a series of probes developed by the Soviet Union – to better understand our neighbouring planet Venus – between 1961 and 1984.

Launched in 1961, Venera 1 lost radio contact before it flew by Venus. Venera 2 failed to send back any important data, but it did fly by Venus at a distance of 24,000 km in February 1966. Venera 3 too lost communication before atmospheric entry, but it did become the first human-made object to land on another planet on March 1, 1966.

With the planned mission including landing on the Venusian surface and studying the temperature, pressure and composition of the Venusian atmosphere, Venera 3 carried a landing capsule that was 0.9 m in diameter and weighed 310 kg. The atmosphere was to be studied during the descent by parachute.

Positive start

Venera 3 was launched on November 16, 1965, just four days after the successful launch of Venera 2. Things went fine for Venera 3 as ground controllers were able to successfully perform a mid-course correction on December 26, 1965 during the outbound trajectory and also conducted multiple communication sessions to receive valuable information.

Among these were data obtained from a modulation charged particle trap. For nearly 50 days from the date of launching, Venera 3 was thus able to give an insight into the energy spectra of solar wind ion streams, out and beyond the magnetosphere of our Earth.

A failure and a first

Just before Venera 3 was to make its atmospheric entry in Venus, on February 16, 1966, it lost all contact with scientists on Earth. Despite the communications failure, the lander was automatically released by the spacecraft.

At 06:56:26 UT (universal time) on March 1, 1966, Venera 3’s probe crash-landed on the surface of Venus, just four minutes earlier than planned. It wasn’t in a position to relay back any information as it had lost contact, but it was the first time an object touched by humans had struck the surface of a planet other than our own.

Success follows

Investigations revealed that both Venera 2 and 3 suffered similar failures owing to overheating of several internal components and solar panels. With regard to Venera 3, its impact location was on the night side of Venus and the site was put in an area between 20 degrees north and 30 degrees south latitude and 60 degrees to 80 degrees east longitude.

Venera 3 tasted success in what was largely a failure, but it did pave the way for several more successes as well. For, Venera 4 became the first to measure the atmosphere of another planet, Venera 7 became the first to achieve soft touchdown and transmit information from another planet, and Venera 13 and 14 returned colour photos of the Venusian surface, days within each other. Venera 13, in fact, transmitted the photos on March 1, 1982, exactly 16 years after Venera 3 had landed on Venus.

Picture Credit : Google

Either now, or when you were younger, you would have surely played with jigsaw puzzles. But have you ever tried to piece together parts from different puzzles and see what you can end up with? What if the same thing actually happened on a celestial scale? The result probably would look something like Miranda.

One of Uranus’ five major moons, Miranda is the innermost and smallest among them. It was discovered by Gerard P. Kuiper on February 16, 1948 in telescopic photos of the Uranian system. Kuiper worked at the McDonald Observatory in western Texas and the photos were obtained using the Otto Struve Telescope at the University of Texas in Austin.

Shakespeare connect

Weeks within its discovery, Miranda’s motion around Uranus was confirmed, on March 1, 1948. With Uranus’ previous moons Ariel and Umbriel discovered in 1851, this made Miranda the first satellite of Uranus to be discovered in nearly 100 years.

Like Uranus’ other major moons Oberon, Titania, Ariel and Umbriel, Miranda’s name too was related to the works of English poet William Shakespeare. Miranda was named for the daughter of Prospero in Shakespeare’s play The Tempest.

At about one-seventh the size of our Earth’s moon, Miranda is among the smallest objects in the Solar System to have achieved hydrostatic equilibrium. Taking 1.4 days to complete an orbit around Uranus and with an orbital period that is also 34 hours, it is tidally locked with Uranus and hence has the same side facing the planet at all times.

Five features

What makes Miranda mysterious, however, is the fact that it has one of the weirdest and most varied landscapes among all extraterrestrial bodies. Scientists agree upon at least five types of geological features on Miranda. These include craters, coronae (oval-shaped features), regiones (areas strongly differentiated in colour or albedo), rupes (scarps or canyons) and sulci (complex parallel grooved terrain).

There are younger, lightly cratered regions and older, heavily cratered regions on Miranda. There are three large coronae in the southern hemisphere, which are kind of unique among objects known in the solar system. These racetrack-like grooved structures are named Arden, Elsinore and Inverness, all locations in Shakespeare’s plays.

Largest cliff in Solar System

The largest known cliff in the Solar System is on Miranda and is known as Verona Rupes, named after the setting of Shakespeare’s Romeo and Juliet. With the cliff face estimated to be 20 km high, this rupees is as many as 12 times as deep as the Grand Canyon in the U.S.

As Miranda is almost invisible to most amateur telescopes, almost everything we know about it is through the Voyager 2 mission. The only flyby of the Uranian system so far was achieved by Voyager 2 in 1986, providing us with a sneak peek of Miranda’s geology and geography.

Considering only the southern hemisphere of Miranda faced the sun during Voyager 2’s flyby and the northern hemisphere was in darkness, only the southern hemisphere has been studied to some extent. Theories have been proposed and discussed as to what might be the reasons for Miranda’s varied geological features. But these mysteries will be solved only with more information and that might well require further missions to Uranus and its system.

Picture Credit : Google