433 Eros

the moons of the planets beyond Earth, the ice giants Uranus and Neptune, Ceres and other bodies later recognized to be part of the asteroid belt, and Pluto, later found to be the largest member of the collection of icy bodies known as the Kuiper belt.

The discovery of other large objects in the Kuiper Belt, particularly Eros, spurred debate about how exactly to define a planet.

In 2006, the International Astronomical Union, IAU, adopted a definition of a planet in the solar system, placing the four terrestrial planets and the four giant planets in the planet category.

Ceres, Pluto, and Eris are in the category of dwarf planet.

In fact, when the motions of the new planet and the Earth combine to bring them to their positions of greatest proximity, the new planet will approach us closer than any other celestial body except our own moon.

Witt named his new planet Eros.

Its size, though small, may prove to be sufficient to bring it within the possibilities of naked-eye observation at the time of closest approach to the Earth.

To astronomers, the great importance of this new planet is due to the following circumstance.

For certain reasons too technical to be stated here in detail, the distance from the Earth to any planet can be determined with a degree of precision which is greatest for planets that are near us.

Thus, in time, we shall learn the distance of Eros more accurately than we know any other celestial distance.

From this, by a process of calculation, the solar distance from the Earth is determinable.

But the distance from Earth to Sun is the fundamental astronomical unit of measure, so that Witt's discovery, through its effect on the unit of measure, will doubtless influence every part of the science of astronomy.

And at first it flew by the asteroid, uh, Mathilde or Mathilde, uh, June 1997.

It came within 753 miles or a little over 1,200 kilometers of its surface, kept going, and eventually orbited an asteroid called 433 Eros in February of 2000.

Yeah, it went psych Mathilde and headed on to Eros.

And-

But Eros is a big deal 'cause it's a big asteroid, right?

It is a big asteroid.

Um, just orbiting Mathilde I think was, like, a first-time thing, like just to see-

Right