Category Space

Why three major telescopes hit the headlines in 2020?

China’s Five-hundred-metre Aperture Spherical Radio Telescope (FAST) passed national evaluation and officially began operation in January 2020. With a dish the size of 30 football fields, it is the world’s largest single-dish radio telescope and the most sensitive listening device. The single-dish radio telescope is made of 4,450 individual panels.

The facility will help scientists learn more about the Universe’s early days, detect low-frequency gravitational waves and hunt for signals that may have been produced by distant alien civilizations.

  • NASA’s Spitzer Space Telescope was retired in January 2020. Launched in 2003, Spitzer studied the universe in infrared light, revealing wonders of the Solar System, our galaxy, and beyond. Among its many scientific contributions, Spitzer studied comets and asteroids in the Solar System and found a previously unidentified ring around Saturn.
  • In April 2020, the Hubble Space Telescope completed 30 years of service. Perched on the low Earth orbit, the telescope’s modest 2.4-metre mirror continues to give us an unprecedented window on the Universe. Thanks to Hubble and the Gaia space observatory, we were able to calculate the age of our Universe, which is approximately 13.8 billion years old. From observations from Hubble, we also learnt that black holes are at the centre of almost every major galaxy.

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  • NASA’s James Webb Space Telescope (JWST) is scheduled to be launched in October 2021. While it is touted as the successor of the Hubble Space Telescope, some scientists believe the two telescopes are actually complementary. Hubble has limited capabilities at near-infrared wavelengths, but it is best suited for observing in the ultraviolet and optical ranges of the light spectrum. Whereas James Webb is perfectly poised to study things in infrared range and these include formation of stars and planets, extremely distant galaxies, and even the atmospheres of exoplanets.
  • The Hubble’s mission ends in 2021, unless NASA decides to extend it.

 

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What is the Demo 2 mission?

NASA, the U.S. space agency, partnered with SpaceX, a private space company, to send astronauts to the International Space Station (ISS) in a commercially built and operated spacecraft. As part of this partnership, the first crewed test flight, Demo-2, was launched successfully on May 30, 2020, from NASA’s Kennedy Space Center in Florida. The SpaceX’s Crew Dragon spacecraft carried NASA astronauts Robert Behnken and Douglas Hurley on the company’s Falcon 9 rocket.

The Demo-2 mission has many firsts to its credit. SpaceX’s Crew Dragon, responsible for mission, is the first privately designed and built spacecraft to carry astronauts to space. The company has hitherto been delivering only cargo to the space station. The launch also marked the first time since the final flight space shuttle Atlantis in 2011 that NASA had sent from the U.S. soil. Ever since the retirement of Atlantis, human spaceflights to and from the ISS have been carried out using Russia’s Soyuz rocket.

With the success of Demo-2 NASA and SpaceX plant to launch the company’s first full mission with astronauts in October. Known as Crew-1, the mission will see three U.S. astronauts and one Japanese astronaut launch in a SpceX Crew Dragon capsule to the ISS.

 

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Which is the closest exoplanet to Earth?

The nearest exoplanet discovered so far orbits the star Proxima Centauri, located 4.2 light-years from our planet.

Proxima Centauri is only 4.2 light-years away. This is still tens of thousands of years by rocket travel, but only a hop, skip and a jump away in cosmic terms. If there were a star closer than Proxima, we would have found it by now. Without any closer stars, astronomers don’t expect to find any closer planets.

There is always the chance of a rogue planet existing closer than Proxima. Rogue planets are those that escaped their star systems and now travel the galaxy solo. But while astronomers think rogue planets are reasonably common, it’s unlikely one would lurk quite that close.

The research team studied Proxima b using the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, or ESPRESSO for short.  ESPRESSO is a Swiss spectrograph that is currently mounted on the European Southern Observatory’s (ESO) Very Large Telescope in Chile. Spectrographs observe objects and split the light coming from those objects into the wavelengths that make it up so that researchers can study the object in closer detail. 

 

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In 2009 NASA launched which mission specifically to look for and detect exoplanets?

The Kepler space telescope is a retired space telescope launched by NASA to discover Earth-size planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched on March 7, 2009, into an Earth-trailing heliocentric orbit. 

Kepler discovered 2,682 exoplanets during its tenure and there are more than 2,900 candidate planets awaiting confirmation — history suggests most of those are the real deal. The mission continued well beyond its scheduled end date, although problems with pointing in 2013 forced mission managers to create a K2 mission in which Kepler swings its view to different spots of the sky.

In the early years of exoplanet hunting, astronomers were best able to find huge gas giants — Jupiter’s size and larger — that were lurking close to their parent star. The addition of Kepler (as well as more sophisticated planet-hunting from the ground) means that more “super-Earths” have been found, or planets that are just slightly larger than Earth but have a rocky surface. Kepler’s finds also allow astronomers to begin grouping exoplanets into types, which helps with understanding their origins.

Kepler’s major achievement was discovering the sheer variety of planetary systems that are out there. Planet systems can exist in compact arrangements within the confines of the equivalent of Mercury’s orbit. They can even orbit around two stars, much like Tatooine in the Star Wars universe. And in an exciting find for those seeking life beyond Earth, the telescope revealed that small, rocky planets similar to Earth are more common than larger gas giants such as Jupiter.

 

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Name the two astronauts who made the first lunar landing on July 20, 1969.

On July 20, 1969, American astronauts Neil Armstrong (1930-2012) and Edwin “Buzz” Aldrin (1930- ) became the first humans ever to land on the moon. About six-and-a-half hours later, Armstrong became the first person to walk on the moon. The Apollo 11 mission occurred eight years after President John F. Kennedy (1917-1963) announced a national goal of landing a man on the moon by the end of the 1960s. Apollo 17, the final manned moon mission, took place in 1972.

At the time, the United States was still trailing the Soviet Union in space developments, and Cold War-era America welcomed Kennedy’s bold proposal. In 1966, after five years of work by an international team of scientists and engineers, the National Aeronautics and Space Administration (NASA) conducted the first unmanned Apollo mission, testing the structural integrity of the proposed launch vehicle and spacecraft combination. 

Then, on January 27, 1967, tragedy struck at Kennedy Space Center in Cape Canaveral, Florida, when a fire broke out during a manned launch-pad test of the Apollo spacecraft and Saturn rocket. Three astronauts were killed in the fire.

 

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Who was the first human to go into space?

April 12 was already a huge day in space history twenty years before the launch of the first shuttle mission. On that day in 1961, Russian cosmonaut Yuri Gagarin became the first human in space, making a 108-minute orbital flight in his Vostok 1 spacecraft.

In 1955, Gagarin was accepted to the First Chkalovsky Higher Air Force Pilots School in Orenburg. He initially began training on the Yak-18 already familiar to him and later graduated to training on the MiG-15 in February 1956. Gagarin twice struggled to land the two-seater trainer aircraft, and risked dismissal from pilot training. However, the commander of the regiment decided to give him another chance at landing. Gagarin’s flight instructor gave him a cushion to sit on, which improved his view from the cockpit, and he landed successfully. Having completed his evaluation in a trainer aircraft, Gagarin began flying solo in 1957.

On 5 November 1957, Gagarin was commissioned a lieutenant in the Soviet Air Forces having accumulated 166 hours and 47 minutes of flight time. He graduated from flight school the next day and was posted to the Luostari Air Base close to the Norwegian border in Murmansk Oblast for a two-year assignment with the Northern Fleet. On 7 July 1959, he was rated Military Pilot 3rd Class. After expressing interest in space exploration following the launch of Luna 3 on 6 October 1959, his recommendation to the Soviet space programme was endorsed and forward by Lieutenant Colonel Babushkin. By this point, he had accumulated 265 hours of flight time. Gagarin was promoted to the rank of senior lieutenant on 6 November 1959, three weeks after he was interviewed by a medical commission for qualification to the space programme.

 

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If you fall into the grip of a black hole, it will stretch you into a strand. What is this phenomenon called?

In astrophysics, spaghettification (sometimes referred to as the noodle effect) is the vertical stretching and horizontal compression of objects into long thin shapes (rather like spaghetti) in a very strong non-homogeneous gravitational field; it is caused by extreme tidal forces. In the most extreme cases, near black holes, the stretching is so powerful that no object can withstand it, no matter how strong its components. Within a small region the horizontal compression balances the vertical stretching so that small objects being spaghettified experience no net change in volume.

The way it works has to do with how gravity behaves over distance. Right now, your feet are closer to the centre of Earth and are therefore more strongly attracted than your head. Under extreme gravity, say, near a black hole, that difference in attraction will actually start working against you.

As your feet begin to get stretched by gravity’s pull, they will become increasingly more attracted as they inch closer to the centre of the black hole. The closer they get, the faster they move. But the top half of your body is farther away and so is not moving toward the centre as fast. The result: spaghettification!

 

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What is Event Horizon?

The ‘event horizon’ is the boundary defining the region of space around a black hole from which nothing (not even light) can escape. In other words, the escape velocity for an object within the event horizon exceeds the speed of light. The name arises since it is impossible to observe any event taking place inside it – it is a horizon beyond which we cannot see. 

When an item gets near an event horizon, a witness would see the item’s image redden and dim as gravity distorted light coming from that item. At the event horizon, this image would effectively fade to invisibility.

Within the event horizon, one would find the black hole’s singularity, where previous research suggests all of the object’s mass has collapsed to an infinitely dense extent. This means the fabric of space and time around the singularity has also curved to an infinite degree, so the laws of physics as we currently know them break down. 

The strength of a black hole’s gravitational pull depends on the distance from it — the closer you are, the more powerful the tug. But the effects of this gravity on a visitor would differ depending on the black hole’s mass. If you fell toward a relatively small black hole a few times the mass of the sun, for example, you would get pulled apart and stretched out in a process known as spaghettification, dying well before you reached the event horizon. 

 

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What are Ploonets?

Astronomers have defined a new class of celestial objects called “ploonets,” which are orphaned moons that have escaped the bonds of their planetary parents.

Although there has yet to be a definitive detection of a ploonet orbiting a star, there are at least a few examples that might fit the bill. The evidence for these potential ploonets comes from perplexing exoplanetary observations that have yet to be adequately explained.

For instance, the researchers of the new paper describe how “moon-star collisions could explain the anomalous spectroscopic features of the stars Kronos and Krios (HD 240430 and HD 240429), which show deep traces of heavy elements.” This is because ploonets are likely made up of largely volatile material — which are light elements and compounds like hydrogen and water that rapidly evaporate — and because ploonets are located so close to their host stars, which exposes them to very strong stellar radiation.

According to the authors, this means that over millions of years, a ploonet will lose a significant chunk of its lighter elements, leaving behind a rather heavy-metal ploonet. If these metal-rich ploonets are then absorbed into their host star, they can produce observational signals that suggest the star instead devoured rocky planets, as may be the case with Kronos.

 

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Studies have suggested that some moons could have moons of their own. What are these called?

A subsatellite is a natural or artificial satellite that orbits a natural satellite, i.e. a “moon of a moon”.

It is inferred from the empirical study of natural satellites in the Solar System that subsatellites may be elements of planetary systems. In the Solar System, the giant planets have large collections of natural satellites. The majority of detected exoplanets are giant planets; at least one, Kepler-1625b, may have a very large exomoon, named Kepler-1625b I. Nonetheless, no “moon of a moon” or subsatellite is known in the Solar System or beyond. In most cases, the tidal effects of the planet would make such a system unstable.

Terms used in scientific literature for moons of moons include “submoons” and “moon-moons”. Other terms that have been suggested include moonitos, moonettes, and moooons.

 

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