Eiffel Tower-size asteroid will harmlessly pass by our Earth

An asteroid that is three times the size of a football field will streak past Earth on December 11, according to NASA but the astronomical object, named 4660 Nereus, is unlikely to be dangerous even if it is almost as tall as the Eiffel tower.

Some media outlets have sensationalized the asteroid, calling it ‘potentially hazardous’ in an awkward abuse of a technical term for rocky fragments left over from the formation of the solar system about 4.6 billion years ago that come within 120 million miles of us.

Potentially hazardous asteroids are almost 500 feet tall or larger, roughly twice as big as the Statue of Liberty is tall, and they approach within about 5 million miles of Earth’s orbit.

Potentially hazardous comets also get unusually close to Earth, but they would have to come much closer to really merit the name.

A Near-Earth Object (NEO) is defined as an asteroid or comet that approaches our planet less than the distance from Earth to the Sun, or about 93 million miles, which is also known as one astronomical unit (AU).

Most NEOs pose no peril at all but a small percentage draws extra scrutiny and are known as Potentially Hazardous Asteroids, a term defined as objects that approach Earth at less than half an astronomical unit.

Millions of asteroids exist: many are shattered remnants of planetesimals, bodies within the young Sun’s solar nebula that never grew large enough to become planets.

Our solar system is huge. There is a lot of empty space out there between the planets.

In an effort to understand these vast distances, imagine the solar system shrunk down to the size of a football field.

On this scale, the Sun, by far the largest thing in our solar system, is only a ball about two-thirds of an inch in diameter— that’s about the width of a dime — so let’s say that coin is sitting on the goal line.

The inner planets — Mercury, Venus, Earth and Mars — are about the size of grains of sand on a football field scale. They would be dwarfed by a typical flea, which is about 3 millimeters long.

Closest to the goal line is Mercury, just under a yard from the end zone (.8 yards to be specific). In reality, the average distance from the Sun to Mercury is roughly 35 million miles (58 million kilometers) or 0.4 AU.

At this scale, Mercury’s diameter would be scarcely as large as the point of a needle.

Venus is next. It is 1.4 yards from the end zone. The true average distance from the Sun to Venus is about 67 million miles (108 million kilometers) or 0.7 AU. Its size on this scale is about 0.15 millimeters.

On to Earth, sitting pretty on the 2-yard line. It is slightly larger than Venus at about 0.16 millimeters.

Pluto is much closer to the opposite end zone. It’s about 79 yards out from the Sun or 3.7 billion miles on average in real distances. That’s 39.5 AU.

Voyager 1, the most distant human-made object, has been in space for more than 40 years and it still has not escaped the influence of our Sun.

On our imaginary scale, Voyager 1 has left the stadium would be beyond about 310 yards from the Sun, possibly out of the parking lot. As of Dec. 4, 2021, Voyager 1 —launched by NASA in the summer of 1977—is about 14.4 billion miles (154.8 AUs) from the Sun — nearly four times the average distance from the Sun to icy Pluto.

The vast majority of known asteroids orbit within the main belt located between the orbits of Mars and Jupiter, or are co-orbital with Jupiter (the Jupiter trojans). However, other orbital families exist with significant populations, including near-Earth objects.

Individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups: C-type, M-type, and S-type. These were named after and are generally identified with carbon-rich, metallic, and silicate (stony) compositions, respectively.

The sizes of asteroids vary greatly; the largest, Ceres, is almost 600 miles across and massive enough to qualify as a dwarf planet.

On our football field, they would be scattered like so many slow-moving linebackers between the four- and eight-yard lines. In real distances that’s roughly 186 million to 372 million miles from the Sun, or between 2 and 4 AU.

On this imaginary scale, these so-called “linebackers” would look like microscopic specks. If you could lump together all the thousands of known asteroids in our solar system, their total mass wouldn’t even equal 10 percent of Earth’s moon.

NASA’s Jet Propulsion Laboratory manages the Center for Near-Earth Object Studies, which tracks comets and asteroids that pass close to Earth’s orbital neighborhood.

Scientists and engineers are developing plans for warning systems and diversion tactics, just in case an asteroid should ever be found in an orbit that could endanger our planet.

The egg-shaped 4660 Nereus asteroid is 1,082 feet long and when it crosses Earth’s orbit on Saturday, Dec. 11, it will be traveling at 14,700 mph but it will be 2.4 million miles away, or around 10 times the distance between Earth and the moon.

This may sound like an enormous gap, but Nereus — named after the Greek sea god who was the son of Gaia, the personification of the Earth — will be closer to us than it has been in 20 years.

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