Lunar Occultation of Mars

Verna and I witnessed the occultation of Planet Mars by Earth’s Moon this evening. At about 7:32 PM Arizona Time, Mars could be seen to disappear behind the Moon and would emerge again about an hour later on the opposite side of the Moon. In the image above (courtesy Griffith Observatory) you can see the tiny Martian dot just below and to the left of the Lunar limb. This is just about the same as we saw it around 7:30PM tonight. We came back outside at 8:30PM and witnessed the re-appearance of the Martian dot on the upper right Lunar limb – very impressive (and nerdy). We both enjoyed it and commented that it was a fun thing to do. We also had witnessed a visible flyover of the International Space Station about fifteen minutes prior to the beginning of the occultation.

From In The Sky — About this occultation:

The Moon will pass in front of Mars, creating a lunar occultation visible from parts of the Americas, Europe and Northern Africa.

Lunar occultations are only ever visible from a small fraction of the Earth’s surface. Since the Moon is much closer to the Earth than other celestial objects, its exact position in the sky differs depending on your exact location on Earth due to its large parallax. The position of the Moon as seen from two points on opposite sides of the Earth varies by up to two degrees, or four times the diameter of the full moon.

This means that if the Moon is aligned to pass in front of a particular object for an observer on one side of the Earth, it will appear up to two degrees away from that object on the other side of the Earth.

At the time of the occultation, the Moon will be 15 days past new moon and will be 100% illuminated.

Radio Check Day

I try and do a check on the functionality and battery condition monthly for each of these little portable hand-held radios. Each is checked against either another radio or via a local radio “repeater.” Three of these are for amateur “ham” radio frequencies while the last pair are GMRS/FRS two-way citizens radios.

I have been a ham radio “nerd” since 1958, and the little radios for the ham bands are for emergencies or maybe a little “rag chew” with other hams from time to time. The FRS radios are for our use when we’re on the road camping and get out of sight of each other. They are also handy for backing the RV up with her outside guiding me inside doing the driving.

The image above (L to R) shows the three ham radios, the charger, a spare battery and the FRS pair hooked to their charger. Click on the image to enlarge.

More Mars Helicopter in 3D

Mars Helicopter Ingenuity in 3D

Another 3D photo from Mars: Ingenuity as seen from the Perseverance Rover on about June 21, 2021, Earth time. Click on the image to enlarge.

From NASA Mars Helicopter Pages:

NASA’s Ingenuity Mars Helicopter is seen here in 3D using images taken June 6, 2021, by the left and right Mastcam-Z cameras aboard NASA’s Perseverance Mars rover. Credit: NASA/JPL-Caltech/ASU/MSSS

As of June 21, 2021, Ingenuity Mars Helicopter has successfully flown its 8th flight, traveling about 525 feet (160 meters) south-southeast from Airfield D to the new Airfield E! This marks the third flight in the Operations Demonstration Phase of Ingenuity, in which the team will continue to push the flight envelope of the aircraft while learning valuable operational lessons. Flight 8 was also the first flight the vehicle executed since performing an update of its Flight-Controller flight software and all telemetry indicates that the update was a success!

In the event that you do not have your 3D anaglyph red/cyan glasses handy, you can see the 2D photo here.

Mars in 3D

Mars in 3D

I generally look at the Astronomy Picture of the Day on a daily basis. Last week, I saw this anaglyph taken by the Mars Pathfinder back in 1997. It shows the Martian landscape and some local artifacts in stereoscopic perspective. Sorry, there is no 2D image available without me digging through NASA and JPL archives, so you better get a pair of 3D glasses to enjoy the image in full perspective.

From APOD:

From July of 1997, a ramp from the Pathfinder lander, the Sojourner robot rover, airbags, a couch, Barnacle Bill and Yogi Rock appear together in this 3D stereo view of the surface of Mars. Barnacle Bill is the rock just left of the solar-paneled Sojourner. Yogi is the big friendly-looking boulder at top right. The “couch” is the angular rock shape visible near center on the horizon. Look at the image with red/blue glasses (or just hold a piece of clear red plastic over your left eye and blue or green over your right) to get the dramatic 3D perspective. The stereo view was recorded by the remarkable Imager for Mars Pathfinder (IMP) camera. The IMP had two optical paths for stereo imaging and ranging and was equipped with an array of color filters for spectral analysis.

Click on the image to enlarge.

Hassayampa River in 3D


It’s been quite a while since I posted an anaglyph photo. Verna took an image pair of the riverbed way back in November of 2015 as we crossed the bridge over the Hassayampa River. I combined the images into the 3D anaglyph above. Click on the image to enlarge.

The river is dry above ground most of the year and looks as it does in this image or in its 2D counterpart (at the link in case you don’t have red/cyan glasses). During monsoon season or at other very heavy rainfall periods, this river gets quite full and flows with vigor downstream. This view is looking toward the north and upstream.