Category Astronomy

What is the Little Green Man?

LGM stands for ‘Little Green Man’. LGM1 is a light deep in space that flashes 30 times a second. It is a pulsar – a tiny, dense neutron star (the remains of a supernova) that flashes out light and radio signals as it spins.

Is it true? Scientists thought pulsar signals were messages from aliens.

Yes. The astronomers in Cambridge, England, who discovered LGM1, wondered at first if they’d come across an alien distress beacon or some other kind of coded message!

Amazing! Neutron stars are super-heavy! They can be just 20 km across, but weigh 50 times more than planet Earth!

How many pulsars are there?

No one is sure, but hundreds have been found since the 1960s, when scientists first spotted the Little Green Man. Special telescopes called radio telescopes are used to ‘listen’ for more pulsars.

Do all pulsars spin at the same speed?

No — even the slowest spin about once every four seconds, but the fastest whizz round many hundreds of times in a single second! Their incredible speeds are thought to be caused by magnetic forces left by a supernova.

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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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Where do old satellites go?

We’ve been satellites to space for a long time. Each satellite serves a different purpose. While some help us predict the weather, some let us watch television, and some help us find our way to different places. However, like all machines, satellites have an expiry date. They can’t go on forever. So what happens to these satellites when they are close to their end?

A cemetery on Earth

When a trusty satellite’s time has come, scientists have two choices depending on how high the satellite is. If it is closer to Earth, engineers will use the last bit of fuel remaining in the satellite to slow it down. This way, it will fall out of space. Towards Earth’s orbit and burn up in the atmosphere. This can be done for bigger satellites, spacecrafts and space stations in low orbit, the solution is for operators to plan for the final destination on Earth to make sure any debris that remains falls in a remote area.

Most likely, this remote area is a place in the Pacific Ocean farthest away from human civilization. It also has a nickname – the Spacecraft Cemetery.

A graveyard in space

The second option that scientists and engineers have is to send satellites in higher orbits even farther away from Earth. This is because it takes a lot of fuel to slow down a satellite enough to fall back into the atmosphere, fuel that these satellites do not have. Hence, with whatever little fuel remains, the satellite is blasted farther into space, never making its way back to Earth.

These satellites are sent into an orbit almost 300km away from the farthest active satellites in space. This place is called the ‘Graveyard orbit’ and is located about 36,000km above Earth.

Some of these satellites will remain in orbit for a long, long time, eventually becoming a part of space debris.

 

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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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