Some astronomy, space and science enthusiasts are claiming that NASA has reported the discovery of a second moon for Earth. Before the gringa’s dear readers get all jittery with excitement and embarrass yourself at a social occasion by repeating this bit of information that is actually a sensationalized truth, let me set the record straight.
First of all, the cosmic object we are talking about is an asteroid called 2016 HO3 . The gringa affectionately refers to this asteroid as HoHoHo. Although it does, indeed, circle our planet while traveling it’s orbit, it lacks certain criteria that would actually define it as a satellite, or, moon. Consider the official definitions for a natural satellite, quasi-satellite, asteroid and moon:
Asteroid: A small, rocky body that orbits the sun.
Moon: (where the Earth is concerned) – the natural satellite of the Earth.
Natural Satellite: An object that revolves around a planet.
Quasi-Satellite: A celestial object that seems to revolve around a planet but really doesn’t or only partially revolves around the planet.
The common thread between the three definitions is orbiting a planet or the Sun. HoHoHo only seems to circle the Earth so it is really a quasi-satellite and not a second moon. It’s a planetary companion, a cosmic friend, a galactic fellow traveler who passes by periodically. Earth and HoHoHo both orbit the Sun and HoHoHo has been our planet’s reliable companion for nearly a century.
Earth once had another friend like HoHoHo but that relationship broke up more than a decade ago. Asteroid 2003 YN107 (I call it Whiney), followed us around for a few years but Earth did not have a strong enough influence. I suppose Whiney was a bit strong-willed and broke free from Earth, going its own way.
However, HoHoHo may find Earth irresistible because, not only has it remained a faithful cosmic friend for over a century, astronomers expect the relationship to continue for hundreds of more years. HoHoHo enjoys a good bit of “me” time, though, spending about half of its time closer to the Sun than Earth. HoHoHo also gets a bit unsteady on its feet, bobbing up and down in its orbit path. This happens because, as it lags behind Earth when it gets closer to the Sun, Earth’s gravitational affect on the asteroid changes. This causes HoHoHo to seem to have a playful personality. When astronomers plot the asteroid’s orbit path, speed changes, tilts and bobs, it looks as if it is playing leapfrog with Earth.
HoHoHo was first spotted by stargazers April 27, 2016 by the Pan-STARRS telescope in Hawaii. Astronomers estimate that HoHoHo’s size is between 120-300 feet (40-100 meters). Amateur stargazers can visit NASA’s online near-earth-object (NEO) resource, the Center for NEO Studies, to find a list of dates and times to anticipate an approach by HoHoHo, as well as other cosmic passersby, to plan your own sighting if you have access to a telescope. Backyard astronomers can also stay up-to-date with cosmic objects to watch by following Asteroid Watch on Twitter.
So, even though the thought of a second moon is titillating, the real story is just as interesting. Keep looking to the stars. Who knows what might show up next?!
Image Credit: www.sciencenews.org