Several comets move towards the Sun and puff themselves up with the heat from the star, so why was Comet ISON special?
Hubble Space Telescope: NASA releases time-lapse sequence of Comet ISON’s movement captured by Hubble Space Telescope! On Tuesday, the US space agency NASA released a time-lapse video of the Comet ISON moving against the stars. The video was made based on images captured by the Hubble Space Telescope back in May 2013, the agency said. Back then, the Comet was moving towards the Sun at a whopping speed of 48,000 miles per hour or over 77,000 kmph.
#HubbleClassic This time-lapse sequence of Hubble images shows Comet ISON moving against a backdrop of stars in May 2013, as it was hurtling toward the Sun at 48,000 miles per hour. The comet broke apart as it passed near the Sun in November that year: https://t.co/whlpqKYLW8 pic.twitter.com/RLA6wAqCOH
— Hubble (@NASAHubble) November 10, 2020
Why is Comet ISON special?
Several comets move towards the Sun and puff themselves up with the heat from the star, so why was Comet ISON special? Back when the scientists found that ISON was travelling towards the Sun, they hoped that it would also flyby the host star and puff up, turning into a Great Comet. However, ISON had other plans. Turned out it did not like the heat, and it fell apart instead.
The news was shared by NASA on December 4 that year, a few days after the Comet ISON was supposed to flyby the Sun on Thanksgiving Day. The scientists had been hoping that the puffing up would turn ISON into a naked-eye comet, but instead, it faded into nothing.
What happened to ISON?
The flyby was scheduled for November 28, 2013, and about 32,000 people joined NASA’s Comet ISON Observing Campaign member Karl Battams to witness the event as ISON made its closest approach to the Sun.
The icy comet was already big and special, and aided by the heat, it would have turned into a great one, which was why all the scientists had been hyped up and buzzing with anticipation of the event. The team was getting live images of the Comet’s approach to the Sun from the Solar Dynamic Observatory and SOHO.
The team saw that as ISON approached the Sun, it brightened and then faded. Another member of the campaign and Battams’ colleague Matthew Knight said that it could have been the disintegration of the Comet.
The Comet was being traced by the Solar Dynamics Observatory all the way to the nearest approach and during the event, it saw nothing. Soon after, the researchers saw as the Sun’s atmosphere expelled a fan-shaped cloud. While scientists are not sure what it was, they think it could possibly be a remnant nucleus which was too small to be caught by the Solar Dynamic Observatory. Another possibility is that the cloud included rubble of fragments that were rapidly vapourising.
In any case, what was supposed to be a day of Comet ISON turning into a Great Comet ended with it being reduced to nothing other than a cloud of dust.
Comet ISON had been discovered in September 2012, and since then, its entire journey from beyond the orbit of Jupiter to the Sun’s atmosphere was tracked by a hoard of spacecrafts, before it plunged into nothingness.