Posts Tagged ‘Tycho Brahe’

04/26/2021 – Ephemeris – There’s a full supermoon tonight

April 26, 2021 Comments off

This is Ephemeris for Monday, April 26th. Today the Sun will be up for 14 hours and 2 minutes, setting at 8:41, and it will rise tomorrow at 6:38. The Moon, at full today, will rise at 8:19 this evening.

The full moon tonight is the full Pink Moon, and a supermoon. As down as I am about full moons due to the fact that they light up the sky and flood out the dimmer objects in the sky, I once in a while stop and view it. The time of the full moon is 11:31 tonight, so when it rises tonight we will be looking at the moon from very nearly the direction of the Sun, so there will be few shadows to be had. The crater Tycho is near the bottom or south end of the moon and has long rays of tiny ejecta craters. The full moon is the best time to see these rays, which are easily visible in binoculars, through which Tycho itself looks like a bright dot. In telescopes Tycho looks like a small bright crater with a dark ring around it. The full moon is super bright. It’s daytime over there.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


High contrast full Moow
The full Moon 7 hours before it was officially full. The contrast was greatly enhanced to bring out Tycho’s ray system. The crater Tycho is at the south part of the Moon and appears bright with a dark ring around it. Credit Bob Moler.
Tycho and Kepler
Tycho and Kepler. Artist for Tycho: Eduard Ender (1822-1883). Artist for Kepler, unknown. Source: Wikipedia

Tycho Brahe and Johannes Kepler are inexorably linked in astronomical history. Tycho was famously stingy with the results of his observations. It was only after his death that Kepler was able to have access to them. Mars was the planet that was hardest to model in both the Ptolemaic geocentric and Copernican heliocentric universes, since both assumed the planetary orbits were circular. So both resorted to epicycles in an attempt to tweak their models in an attempt to fit with observational reality.

Both Tycho and Kepler have craters named for them on the Moon. Tycho gets a splashy crater on the southern part of the Moon. Kepler, however, gets a small crater on the plains of Oceanus Procellarum west of the crater Copernicus on the left side of the Moon, as we see it

10/23/2012 – Ephemeris – The remarkable lunar crater Tycho

October 23, 2012 Comments off

Ephemeris for Tuesday, October 23rd.  The sun will rise at 8:08.  It’ll be up for 10 hours and 35 minutes, setting at 6:44.   The moon, 2 days past first quarter, will set at 2:52 tomorrow morning.

Tonight the moon’s advancing sunrise line will reveal a young crater near the bottom of the moon.  That crater is Tycho.  In binoculars or a telescope it’s features appear sharper, and its floor deeper than the surrounding craters.  Its age is in the range of hundreds of thousands of years rather than billions.  Tycho has an extensive ray system that extends thousands of miles across the face of the moon.  That is best seen at full moon, and the rays are probably a huge number of craterlets.  They are normally shadow filled but at full moon are fully illuminated accentuating the brightness of the rays.  The crater was named for 16th Century Danish astronomer Tycho Brahe, the greatest observational astronomer before the invention of the telescope. [ His observations allowed Kepler to formulate his three laws of planetary motion.]

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


The crater Tycho and one of its rays at 9 p.m. on October 23 2012.  Created using Virtual Moon Atlas.

The crater Tycho and one of its rays at 9 p.m. on October 23 2012. Created using Virtual Moon Atlas.