Human Journey

Johannes Kepler: One of Newton’s Giants?

First, allow me to extend a warm welcome to the 3,500+ astronomers, astronomy buffs, writers, friends, and family now in Washington, D.C., for the 215th meeting of the American Astronomical Society.

Welcome to my home town, and thanks for bringing the meeting to me for a change!


—Image courtesy NASA

Day One of the conference brings the news that five more extrasolar planets—or exoplanets—have been added to the roster of known worlds, thanks to NASA’s Kepler space telescope.

With the addition of last fall’s 32 newbies, the Kepler find brings the official known exoplanet count to 420.

Exoplanet aficionados might say, So what? The new worlds don’t seem all that special, considering that they appear remarkably similar to the hundreds that have already been found.

Like most of the known exoplanets, they’re big—from Neptune’s size to larger than Jupiter—and they’re hot. That means the chances of setting up the first human colony on any of them are pretty much nil.

What’s exciting is that the find shows NASA’s nearly $600-million Kepler spacecraft is working perfectly, spotting planets in unprecedented detail.

And that means Kepler has every chance of achieving its main goal: finding small, rocky worlds within their stars’ habitable zones—Earth 2.0.

So what gives, Google? What’s with the falling apples for Sir Isaac Newton on a day when Johannes Kepler should be in the limelight?

German mathematician Kepler was born in 1571 and died in 1630—more than a decade before Newton’s birth. But his work is often credited with helping dear Isaac formulate his theories of universal gravitation.

[Surely that means Kepler was one of the “giants” Newton stood on in his famous quote!]

According to NASA, Kepler: The Scientist was the first person to correctly define the laws of planetary motion, and he made a bunch of innovations in optics, including the first explanation of exactly how a telescope works.

A few fun facts about Kepler:

  • he taught arithmetic, geometry, and Virgil (ancient Roman poet) at a Protestant seminary in Graz, an Austrian province
  • his work on celestial mechanics got him invited to Prague by Tycho Brahe to calculate new orbits for the planets
  • he published his first two laws of planetary motion in 1609’s Astronomia Nova
  • his mother was tried for witchcraft in 1620
  • he demonstrated that Jesus was born in 4 B.C., based on his mathematical studies of chronology

All this and more [minus the witch stuff, maybe] makes Kepler a great namesake for Kepler: The Spacecraft.


—Image courtesy NASA

The orbiting observatory uses carefully calibrated optics to stare at 100,000 stars for three and a half years watching for the changes in brightness that signal transits: when a planet crosses in front of its star as seen from Earth.

The hope is that the recently launched craft’s sensitivity and the loooong exposure will reveal proof of smaller, rocky worlds like Earth orbiting just far enough from their stars for life to happily exist.

The whole premise of looking for and classifying planets via transits is based on what we know about the way planets orbit stars, and what we know about that stems from Johannes.

So let’s get with the program, Doodlers. I expect to see a Kepler-themed picture on my desktop by 3 a.m., no excuses.


    Sorry,I don’t think Kepler’s laws are right.Newton’s mechanical laws are falsified by the mathematicians to prove Kepler’s wrong laws.The orbits are not elliptical,but cardioidal looking spirals.The sun is not at a focus of such ellipses but at the center of these spiralled orbits.There is no aphelion,no perihelion.Swept areas in equal time are not equal.Newton’s correct law about periods is not valid for the planets as time and distances to the sun are variables.For example if today 1 year=365 days,(4 342 266 160) years ago 1 year was (39,24) days.

  • Michael Roy
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    This is so amazing that we are finding all these new planets. We need to research these more in the future. I just want to see some life in another planet.
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    Definitely agree with what you stated. Your explanation was certainly the easiest to understand. I tell you, I usually get irked when folks discuss issues that they plainly do not know about. You managed to hit the nail right on the head and explained out everything without complication. Maybe, people can take a signal. Will likely be back to get more.

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