Giant ‘potentially hazardous’ asteroid will fly safely by Earth in April

For some more good news on this April 1: a giant, “potentially hazardous” asteroid will miss us this month. NASA has named the asteroid 1998 OR2. It is about the width of Manhattan Island and could wreak havoc if it crashed into Earth.

However, at its closest it will be 3.9 million miles from us (more than sixteen times the average distance between us and the moon). We won’t see it again until May 18, 2031. It will return again in 2048, 2062, and 2079, when it will only be 1.1 million miles away.

When we read about 1998 OR2, here was our collective thought: How do NASA’s experts know how far it will be from us? Or when it will return?

We had a similar question early yesterday morning. Saturn, Mars, and Jupiter were all visible in the predawn sky. Or so a website told us. We would have otherwise been unable to name them or to know that they are planets in our solar system.

So we equipped ourselves with a “Sky Ap” to name the planets and constellations and loaded our brains with math.

Like when we try to create a differential equation with which we can numerically solve to plot the orbit of an asteroid around Jupiter so far we have assumed the mass of jupiter is 0.001 of the mass of the sun. We are also assuming that the asteroids are massless so that they possess no gravitational force on Jupiter and Jupiter’s orbits are circular.

So we came up with something like this…GMm/r2=mv2y/rGMm/r2=mvy2/r, thus vy=GM/r−−−−−√vy=GM/r, where vyvy is the y component of the asteroids velocity, rr is the semi-axis diameter of the orbit. We can also write the total energy of the asteroid to be E=1/2m(GM/r)GmM/r=GMm/2rE=1/2m(GM/r)−GmM/r=−GMm/2r, which after some rearranging yields r=GMm/2E.

Of course that will not solve the problem… but its a start.

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