August 23 – In late August 2006, new discoveries upended our conventional view of our comfortable solar system. Scientists have determined that Pluto is not a planet after all.
Some space nerds want to mourn the loss of Pluto’s status or celebrate scientific progress by commemorating August 24th each year as Pluto Demotion Day.
To understand its importance, we need to go back to the 1800s, when astronomers noticed irregularities in the orbit of the eighth planet, Neptune. This has led astronomers to look deeper into the universe in search of a theoretical Planet X.
Eventually, they discovered that tiny Pluto was following a strangely tilted, elongated orbit between 2.8 and 4.6 billion miles from the Sun. It takes Pluto 248 years in our years to complete her orbit around the Sun.
Astronomers declared Pluto a planet in 1930, but its weak gravity could not fully explain Neptune’s orbital wobble.
Scientists continued their search, and by the 1990s were swamped with discovering many similarly sized objects in the same distant space. This turns out to be a second asteroid belt, much larger than the better-known asteroid belt between Mars and Jupiter.
Its outer belt, the Kuiper Belt, has cataloged thousands of large objects, at least 200 of which are larger than Pluto. Overall, the Kuiper belt probably contains “hundreds of thousands of ice bodies larger than its diameter (62 miles) and an estimated 1 trillion or more comets,” according to NASA.
Maybe Pluto wasn’t so special after all. The International Astronomical Union felt obligated to formally define a “planet” for the first time and address the fate of Pluto.
The planets determined by the IAU are:
— orbits the sun.
— exert enough “self-gravity” to draw itself into a “nearly circular” shape, and;
— Throw or swallow small objects to exert enough gravity to dominate and sweep around their orbits.
Pluto meets the first and second criteria, but its gravity is too weak to check the third box. It turned out to be another ice stone roaming around the Kuiper Belt without enough gravitational force to clear its own path. We have designated many of its smaller companions as “dwarf planets.”
As painful as it is, Pluto maintains many fans and defenders. In particular, Alain Stern, lead scientist on the New Horizons space probe, reveals a geologically complex world with mountains, potential oceans, and a thin atmosphere in 2015 flyby photos.
There are also mystical, vast (1,000 miles wide) brightly colored regions that look uncanny like Valentine’s hearts that may be made of ice and snow. New Horizons has taken stunning pictures of Pluto’s five moons, the smallest of which is just 10 miles.
Complex geology needs to be added to the definition of “planet,” Stern said, arguing that Pluto should re-enter the celestial VIP club.
In 2007, the American Dialectic Society coined a new verb, “to pluto,” which means “to demote or downgrade.” The Society noted, “The huge emotional reaction of the public to the demotion of Pluto. …[we]still feel connected to the planet that once was.”
telescope needed to see pluto
We suggest you check in on cold and lonely Pluto on Wednesday, the day of the demotion. Unfortunately, dwarf planets are so small and far away that they cannot be seen without a telescope.
If you have a telescope, know the following: On Wednesday, Pluto rises east-southeast after 6:30 p.m., remains on the southern horizon (below the triangular constellation Capricorn), transits west, and sets again in the west-southwest around 3:15 a.m. increase.
In the months that follow, Pluto rises and sets faster and faster, making it even harder to see. Try again in July 2023, when Pluto rises late at night and doesn’t set until around 7am.
Pluto size up
- diameter (miles)
- Jupiter: 86,881
- Earth: 7,917
- Ganymede (Jupiter’s largest moon): 3,273
- Mercury: 3,032
- Earth’s Moons: 2,160
- Pluto: 1,477
- Charon (Pluto’s largest moon): 753
- Styx (Pluto’s smallest moon): 10
— Scott Hewitt
Pluto Demotion Day Chance to pay tribute to uninherited dwarf planet
Source link Pluto Demotion Day Chance to pay tribute to uninherited dwarf planet