My Science School

People living in the Northern Hemisphere are in the best position to observe these beautiful meteor shows. For example, north America is right below the region of the sky where the January Quadrantids shower appears. Meteor showers can be seen at different times of the year depending on when Earth is going to pass through the comet’s or asteroid’s path. Some meteor showers happen annually; other appear once in a few years. Some of the best shows – meteor storms – happen just once or twice in a lifetime.

The best time to watch them is the pre-dawn hours, when the part of Earth you are standing on is facing the direction of Earth’s orbit. In the late evening hours the meteors are less frequent.

What can go wrong?

A bright moon can dim the light of the meteor show, fading out all but the brightest meteors. Local light pollution can affect our ability to view a shower. To view a meteor shower in all its glory, go to a rural location. Weather can also play spoilsport for a good view of meteor showers. A clear sky is what we need, which is why meteor showers during the summer are more visible than those that happen in the winter months.

 

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Meteor showers are named for the constellation from where they appear to emerge. For example, the Orionids meteor shower, which occurs in October every year, appears to be originating near the constellation Orion the Hunter, Perseid meteors seem to be coming from the Perseus constellation.

In some years you see more meteor showers than in others, depending on atmospheric conditions.

Astronomers sometimes find new meteor showers, like the Camelppardalis in 2014. The shower happened after the debris trail of Comet 209P/LINEAR intersected with Earth. Most meteors become visible when they come within 60 miles (96.5 km) of the Earth. On average, meteors can speed through the atmosphere at about 30,000 mph (48,280 kph) and reach temperatures of about 3,000 degrees Fahrenheit (1,648 degrees Celsius).

Let’s look at the popular meteor showers.

Leonids

The Leonids meteor shower is the brightest and most impressive one. It can produce a meteor storm that showers the sky with thousands of meteors per minute at its peak. In fact, the term “meteor shower” was copied after astronomers observed one of Leonids’ most impressive displays in 1833. The Leonids occur every November, but the shower’s most beautiful display happens at intervals of about 33 years. The last one lit up the Earth’s sky in 2002. A Leonid shower is not expected until 2028.

Perseids

Perseid may have been introduced into English from Italian Perseidi, coined by the Italian astronomer Giovanni Schiaparelli (1835-1910). Perseid ultimately comes from Greek Perseids “offspring or daughters of Perseus,” because the meteors looks like they are coming from the constellation Perseus. Perseid entered the English language in the 19th century. The Perseid meteor shower is from the comet Swift-Tuttle and happens in August. It is the most widely watched meteor shower of the year, peaking on 12 August with more than 60 meteors per minute.

Orionids

The Orionid meteor shower produces meteors from Halley’s comet, which orbits the sun every 75 to 76 years. The Orionid shower happens every October and can last for a week. It is a show of 50 to 70 shooting stars per hour at its peak.

Quadrantids

The Quadrantid meteor shower comes from the debris of an asteroid called 2003 EHI1. Astronomers believe this is part of a comet that broke apart centuries ago. The debris enters Earth’s atmosphere in early January. This meteor show is brief but spectacular.

Geminids

Like the Quadrantids, the Geminid meteor shower also came from dust particles of an asteroid called 3200 Phaeton. As the name suggests, the shower emerges from Gemini constellation. Meteor showers are mostly from comets, so having an asteroid as a parent make the Quadrantids and Geminids different from other meteor shows. The Geminids happen in December and spray up to 40 meteors per hour.

The Eta Aquarids

The Eta Aquarids is made up of the remnants of Halley’s coment. The show happens in May.

Lyrids

Lyrids, which has been written about for more than 2000 years, appears in late April.

 

Picture Credit : Google

A meteor shower is a celestial show that you get for free – no tickets, no telescopes, no binoculars. You don’t have to travel to a high mountain to view it. All you have to enjoy this show is a dark night. Just get up in the middle of the night, go to the backyard and find a perfect spot to watch it.

Let’s see what a meteor shower is. A meteoroid is a piece of debris – the size of a pebble – which travels in outer space. Large meteoroids are believed to come from the asteroid belt. Some of the smaller meteoroids may have come from the Moon or Mars. If a meteoroid enters the Earth’s atmosphere, it’s called a meteor, or shooting star. If part of that meteor travels through the atmosphere and hits the Earth, it’s a meteorite. A lot of meteorites never end up being meteors or meteorites.

When the meteor (or a meteoroid) falls toward the Earth, the resistance (or drag) from the Earth’s atmosphere makes it extremely hot. The hot air around the rock glows as the rock zips through the atmosphere. When Earth comes across many meteoroids at once, we call it a meteor shower. According to SPACE.com, meteor showers occur when dust or particles from asteroids or comets enter Earth’s atmosphere at very high speed. When they hit the atmosphere, meteors rub against air particles and create friction. The heat vaporises most meteors, making them into shooting stars. We see meteor showers when the Earth rushes through the trail of particles left behind by a comet or asteroid.

Meteor showers may appear anywhere in the sky, but their “tails” usually point to the same spot in the sky. That’s because all the meteors travel to Earth at the same angle. When they are close to Earth, they look like they are getting away from one another. This is just an optical illusion.

 

Picture Credit : Google

If you were to think of a laboratory in space, you would probably think about the International Space Station (ISS). A habitable artificial satellite in low Earth orbit, the ISS is a joint project by a number of space agencies and its usage is governed by treaties and agreements. The ISS, however, isn’t the first space station built by humans. There were precursors to it, one of which is the Skylab.

NASA had the idea for a space station for years before the Skylab was eventually launched. It was believed to be the dream of American-German space architect and Apollo rocket engineer Wernher von Braun, who had long wanted to build a human outpost that would let people live and work in space for extended periods of time.

Use unused hardware

With the space race and the mission to moon dominating the 1960s, the idea for a space station picked up pace only after that. NASA began an Apollo Applications Program to utilise unused hardware from their missions to the moon and one of the ideas to pursue was that of the space station.

The design evolved over the years and the Skylab consisted of four components. The Orbital Workshop (OWS) was the main compartment for living, working and sleeping; the Airlock Module (AM) allowed astronauts to conduct space-walks; the Multiple Docking Adapter (MDA) enabled rescue operations; and the Apollo Telescope Mount (ATM) contained telescopes for observations and solar arrays for additional power.

Repair work possible

Launched on May 14, 1973, Skylab was faced with a crisis right at the start. A micro-meteoroid shield that was to function as a thermal blanket and shelter Skylab from debris accidentally opened just over a minute after the launch. This meant that the temperatures inside the space station rose to intolerable levels.

While the launch of the first crew was delayed because of this incident, their first task eventually became to salvage this situation when they made their way on May 25. Even though it was no easy task and it was definitely frustrating for the crew members involved, they eventually succeeded after a few days. They were able to erect a sun shade, deploy the array that was previously stuck and begin their work inside the space station. It showed that it was possible for space-walking astronauts to fix badly damaged space station while it was still in orbit.

Three successive three-man crews lived aboard the Skylab. While the first one – the ones who performed the repair – stayed in space for 28 days, those in the second and third crews lasted 56 and 84 days in orbit respectively.

Superhuman expectations

Skylab’s second crew were super productive in getting their tasks done, that they wanted more. So much so that it set unrealistic expectations of what can be achieved in space. By the time the third crew returned to Earth on February 8, 1974, they had accompanied a lot of scientific work, but not before complaining of being overburdened with superwoman expectations.

Even though there were plans for more crews to be sent to Skylab, the third turned out to be the last as well owing to financial constraints and NASA’s other objectives. The three crews had managed to conduct 270 experiments in life sciences, solar astronomy and Earth observations. In fact, over 700 hours were spent observing the sun, resulting in over 1,75,000 solar pictures.

Intense solar activity heating up Earth’s atmosphere meant that Skylab’s orbit decayed faster than NASA’s expectations, forcing them to pursue the only course of action possible. They adjusted the station’s path so that it wouldn’t hit populated areas. Upon re-entering on July 11, 1979, it broke up in the atmosphere and showered debris over the Indian Ocean and Australia.

Skylab provided for plenty of learning, especially with respect to the human element in long-haul space-fights. The focus was placed strongly not only on the nutritional and physical exercise requirements for human beings in space, but also other mental concerns they might face, including those caused by their workload and the lack of family life. Thanks to the Skylab, all these areas are now addressed for astronauts aboard the ISS.

 

Picture Credit : Google