Taiwanese team discovers clues from Japanese and US satellite images that could be a candidate for the solar system's "ninth planet." What do the future hold?
//Summary - Level-B2//
A Taiwanese research team has found possible evidence of a ninth planet in our solar system by analysing old infrared data from Japanese and US satellites. ‘Planet 9’ is a theoretical planet beyond Neptune, possibly larger than Earth but smaller than Neptune. Its gravity may explain the unusual orbits of some distant objects. However, astronomers stress that more data is needed to confirm this discovery. The upcoming Vera Rubin Observatory may help find it within 18 months. While hopes are high, scientists remain cautious until more evident proof appears. The search continues for this mysterious, distant world.
A)
A Taiwanese research team searching for the unknown 'ninth planet', thought to exist in the solar system's outer reaches, has found evidence of a potential candidate in archived images from a no longer operational Japanese and American infrared astronomy satellite.
'Planet 9', also known as 'Planet X', is a hypothetical entity without observational evidence. Still, astronomers are increasingly confident that they will soon be able to either discover it or rule it out.
B)
Search for 'Planet 9':
There are currently eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. This number has remained unchanged since Pluto, once considered the ninth planet, was reclassified as a dwarf planet in 2006.
Beyond Neptune's orbit lies the Kuiper Belt, home to dwarf planets such as Pluto and other small celestial bodies. This region is also said to be the origin of short-period comets.
Some astronomers believe this region may contain a 'ninth planet' that orbits 20 times farther than Neptune and is estimated to have a mass larger than Earth's but smaller than Neptune's.
If this planet exists, it could be discovered within 18 months.
C)
What is the 'Planet 9' hypothesis?:
The Kuiper belt is a densely packed area of small objects. Six of these objects — Sedna, 2012 VP113, 2004 VN112, 2010 GB174, 2013 RF98 and 2007 TG422 — have highly elongated, elliptical orbits that are strikingly similar. This could be due to the gravitational influence of an unknown planet.
However, if the planet does exist, it isn't easy to see using standard observational methods because it orbits far beyond Neptune and reflects very little sunlight. Its orbit is also very slow, making it difficult to pinpoint.
D)
Potential candidate for 'Planet 9' discovered?:
A research team led by Professors Terry Long Phan and Tomotsugu Goto, from the Institute of Astronomy at National Tsing Hua University in Taiwan, conducted a study using the IRAS infrared astronomy satellite (in operation from 1983 to 1984) and the Japanese astronomical satellite Light.
The researchers say they have discovered a potential candidate for the 'ninth planet' by analysing archived data from the far-infrared all-sky survey conducted by the Space Telescope (2006–2011).
E)
Infrared observations can detect faint objects that optical observations cannot see. The 23-year separation between the two infrared satellites was long enough to confirm the orbital motion of the slow-moving candidate object.
Pre-reviewed paper:
According to the study, the team found one object in the IRAS dataset that was not seen in the AKARI dataset, and one object in the AKARI dataset that was not seen in the IRAS dataset. Crucially, these were in the same position as Planet 9's likely orbital transition.
However, the research team points out that detection from the AKARI and IRAS data is insufficient to determine the candidate object's complete orbit and that follow-up observations are necessary.
F)
Is 'Planet 9' real?:
Astronomers searching for 'Planet 9' are excited by the emergence of a potential candidate, but remain sceptical. This week, Michael Brown, a professor of planetary astronomy at the California Institute of Technology, told the astronomy website EarthSky: "It's an excellent paper and uses the right methodology".
However, he also expressed the view that finding just one pair of data with matching celestial body positions does not constitute evidence of the existence of an unknown planet.
The Thrilling Search for Planet 9 Goes On
https://www.youtube.com/watch?v=n9EzjGMcHCs
G)
Brown proposed the 'Planet 9' hypothesis in 2016 with his colleague Konstantin Batygin to explain the similar orbits of six small bodies in the outer solar system.
'The obvious question here is: does it exist? That's a difficult question to answer,' said Brown. 'Just because there are two data points doesn't convince me. I need to see a third, a fourth, maybe a fifth or sixth.'
H)
Hopes for the Rubin Observatory to start operating:
Brown and his team are searching for 'Planet 9' by analysing images obtained through the Zwicky Transient Object Facility (ZTF) at Palomar Observatory in the United States and the Pan-STARRS all-sky observation project in Hawaii. However, they have not been successful so far.
However, if "Planet 9" really does exist, there's a good chance we could find it at the Vera C. Rubin Observatory in Chile. The observatory's Large Synoptic Survey Telescope (LSST) is the largest digital camera.
It will take high-resolution images every 39 seconds to create a time-lapse video of the universe over 10 years. If 'Planet 9' is lurking in the outer solar system, the Rubin Observatory should be able to find it.
I)
'Even if someone handed me a billion dollars and told me to build a telescope to find Planet 9, I wouldn't take it because the Vera Rubin Observatory is perfect,' said Brown.
'It would take pictures of the sky night after night, and all we would have to do is look for a dim object moving slowly across it.'
If 'Planet 9' is brighter than the mid-range estimate, it will likely be discovered within a year and a half of the Vera Rubin Observatory's scientific operations beginning. Until then, the unknown planet will remain one of astronomy's greatest mysteries.
Taiwanese team discovers clues from Japanese and US satellite images that could be a candidate for the solar system's "ninth planet." What do the future hold?
https://forbesjapan.com/articles/detail/79386
