The Geminids meteor shower, believed to be the strongest of the year 2020, was active from December 4 to 20, 2020, with December 13 and 14 considered to be the best nights for viewing them (some meteor activity could still be visible in the days before and after this peak).
The expected rate of shooting stars during the peak of the Geminids meteor shower in 2020 was 150, according to the International Meteor Organization (IMO). Geminids rate was to be better in 2020 because the showers’ peak overlapped with a nearly new moon, which meant that there were darker skies and no moonlight to wash out the fainter meteors. This shower is among the handful that produce a consistently high number of meteors, with over 100 an hour, often more than two a minute.
To spot the radiant (the place in the sky where they appear to originate from), one has to sight the Gemini constellation (and so the showers are called ‘Gemenids’).
The Geminids meteor showers are not unique events; they happen constantly and have been happening for a long time. One of the first recorded observations was in 1833 in USA, from a riverboat on the Mississippi River. However, they are considered as one of the best meteor showers every year because the individual meteors are bright, and they come fast and furious. In 2019, because of the nearly-full moon, the Geminids produced about 20 to 30 meteors visible per hour. The Geminids are visible from both hemispheres. Although it is best visible from the Northern Hemisphere, Geminids meteors can also be spotted from the Southern Hemisphere. Scientists say that Jupiter’s gravity has tugged the stream of particles from the shower’s source, the asteroid 3200 Phaethon, closer to Earth over the centuries, and so the showers may be seen more clearly with the passing years.
The National Aeronautics and Space Administration (NASA) states that Geminids travel at a speed of 79,000 mph or (35 km/s) or (22 miles/s) i.e., over 1000 times faster than a cheetah and about 250 times faster than the fastest car. They can be easily spotted but tend to disintegrate completely at about 39 km (24 miles) of altitude.
Asteroid Associated with the Geminids
The Geminids showers are associated with the near-Earth object 3200 Phaethon, an asteroid. Recorded on October 11, 1983, the asteroid is 5.8 km (3.6 miles) in diameter. Unlike many asteroids, Phaethon is in a comet-like orbit and releases dust, which has the Geminids meteors, possibly due to its getting extremely heated up by the Sun. It is thought that the asteroid that may have undergone a collision with another object in the distant past to produce the stream of particles that form the meteros of the showers.
The asteroid orbits the sun every 1.4 years, coming close to the Earth rarely. It passes very close to the sun: inside of Mercury’s orbit and only 0.15 astronomical units from the sun.
The distance between the sun and the Earth is called an astronomical unit—about 93 million miles or 150 million km.
Meteor Showers
Meteors are bits of rock and ice that are ejected from mostly comets that are prone to shedding material as they evaporate approaching the Sun. They can also fall from asteroids as they manoeuvre around their orbits around the sun. According to NASA, over 30 meteor showers occur annually and are observable from the Earth.
As meteors pass through the atmosphere, they leave behind streaks of glowing gas that are visible to the observers. When they fall towards the Earth, the resistance makes them extremely hot.
Meteors are best visible on a cloudless night and when the Moon is not extremely bright. Chances of a successful viewing are higher from locations far away from the lights of cities. But pollution makes viewing meteor showers difficult. In areas where there is no light or air pollution, they can be seen without any special equipment. Viewers need to make sure to give enough time to let the eyes adjust to the darkness, which can take about 30 minutes. Interestingly, it is recommended that those who want to view the showers should not use their mobile phones for some time, as bright light from screens such as TV screens, mobiles and so on affect night vision.
‘Meteor’ Terms
Meteoroids are rocks in space that are sent towards the Earth and are about to collide with the Earth’s atmosphere. Those that are seen streaking through the atmosphere are called meteors; and if they reach the ground, the rocks are called meteorites (not all meteoroids reach the ground as many of the particles are too small to survive the fall). A series of meteorites, when encountered at once, is termed a meteor shower.
Comparing Geminids and Other Meteor Showers
Geminids and Ursids meteor showers are different from other meteor showers in that their origin is not to be found in comets. Soon after the Geminids meteor shower in December 2020, viewers in the northern hemisphere were expected to see the Ursids meteor shower, active from December 17 to 26 and peaking right on the night of December 21 to 22. However, the rate of Ursids is much less than Geminids: if Geminids viewers in the northern hemisphere could expect to see about 60 meteors per hour, observers of Ursids showers can typically see 5–10 meteors per hour.
The Orionids meteors emerge from the comet named 1P/Halley and they make their presence annually around October.