Are scientists a step closer to finding Planet Nine — the massive, undiscovered world thought to lurk somewhere in the distant solar system — through evidence from NASA's Cassini spacecraft?
Just recently, Caltech planetary scientists Mike Brown and Konstantin Batygin presented proof of Planet Nine's existence, estimating that it may be revolving around the sun on a super-elongated orbit, taking 10,000 to 20,000 years to complete. They based their findings on a huge, icy cosmic object situated around the outer solar system's dark abyss.
This month, some observations on the Cassini spacecraft, which is orbiting Saturn, are fueling hope that the missing planet may soon be detected. Some experts are, in fact, estimating that it can happen in as little as one year.
"Evidence is mounting that something unusual is out there — there's a story that's hard to explain with just the standard picture," says cosmologist David Gerdes in a Scientific American report, finding himself — rather unexpectedly — as one of the scientists studying the team's calculations.
So how has the Cassini spacecraft become involved in the probe?
Brown's team based their conclusions on the Planet Nine's assumed gravitational effect on some objects on the Kuiper Belt, which are icy bodies circling the sun beyond Neptune's orbit. In theory, the planet's gravity should also slightly tug on the planets, moons, and orbiting spacecraft.
The team of Agnes Fienga at France's Cote d'Azur Observatory then checked if the theoretical model that they have been working on for more than 10 years, with Planet Nine's addition, could answer for slight perturbations detected in Cassini's orbit.
The missing piece of the puzzle just might be Planet Nine, since the eight planets of the solar system as well as 200 asteroids and five of Kuiper Belt's largest objects cannot be accountable for it.
The team explained Cassini's orbit quite impressively when they compared the data with the updated, Planet Nine-powered model. The so-called sweet spot places Planet Nine around 90 billion kilometers (55 billion miles) away facing constellation Cetus.
If Planet Nine is indeed situated toward this constellation, it could also be picked up by the observation project Dark Energy Survey, which is designed for investigating the universe's acceleration. The area of focus is "smack dab in the middle" of the footprint of the survey, reports Gerdes.
Another opportunity to catch Planet Nine is to seek out the millimeter-wavelength light it is radiating based on its own heat, a measure proposed by exoplanet astronomer Nicolas Cowan. The scientist believes that the elusive planet might finally appear in surveys of the cosmic microwave background (CMB), the massive big bang afterglow.
The discovery of Planet Nine, thought to be 10 times the size of Earth and orbiting the sun 20 times the distance of Neptune on average, continues to excite experts, despite NASA saying back in February that it remains theoretical and unproven.
"I am optimistic that if this ninth planet exists, it will be discovered in the next 2-3 years," Dr. Dimitris Stamatellos of the University of Central Lancashire tells the Cyprus News Agency Monday.