Ags

@Mr Spock I am curious how the SLV 2.5 compares to the Nagler Zoom at 3mm?

I use an ASI 485 MC, so I only have a small 6x11 mm sensor. That's a bit too zoomed in with my 500 mm focal length Long Perng 90. For example, stars are a little big with the fast apo, but as the overall image is quite small due to the sensor star size is exaggerated. I am considering of getting a Long Perng 0.6 Reducer/Flattener to shoot somewhat wider vistas. Not sure if the reducer would work in an f5.6 scope?

Tonight's Moon.

Made obsolete by the Svbony SV215 3-8 Zoom?

Despite having started this thread, I am a bit late to the party - mine is now ordered and should arrive in a couple of weeks.

I think there are laws (with loopholes) that bssically let you you have a fight with your neighbor. I want a law that prevents the companies from selling or installing problem lighting.

I've shared it on Mastodon - they be crazy political there!

Signed and shared. I particularly like the way the petition is framed as being about our right to darkness.

Asteroids are generally thought of as rocky rubble, whereas Ceres is perhaps 50% water by volume. Of all the bodies in the entire inner solar system (everything within Jupiter's orbit), only Earth has more water than Ceres. Those white patches in Occator crater hold the clue to the mystery - the salt patches are not common table salt, but are a more diverse mixture including ammonia salts. Ammonia is very volatile and indicates Ceres formed further out beyond Jupiter. It was kicked into the Asteroid Belt when Jupiter's own orbit went through changes in the early days of the solar system. It makes me think that in the early days, Ceres may not have been a faint object in the Earth's sky - perhaps it was surrounded by a splendid cometary halo as its outermost ice layer sublimated, eventually leaving behind the dry salty clay crust. Even today Ceres has a tenuous atmosphere of water vapor (although I think calling it an atmosphere suggest some degree of gravitational binding, whereas it really seems to be H2O that hasn't drifted away yet).

Gorgeous!

I want to try spot it if we get another clear night this year, I confess I have never seen Ceres myself. I think it is wonderful how we send probes to new locations, and every time the target brings surprises and becomes more interesting... Ceres has a lot of water - estimated to be as much as all the fresh water on Earth. I do think that if I ever stood on the surface of Ceres, I would have the terrifying feeling that I could just drift off into space if stepped forward too vigorously. No risk of that - the escape velocity is is over 1000 km/h, but the high jump record should be something like 80 meters.

I think Ceres is a much neglected member of our solar system, probably because it is 'only' an asteroid (actually it is a dwarf planet, and when it was discovered it was regarded as a full-strength proper planet). It is a unique world, made of brine and mud and very soft. It is the only round, brown body in the solar system. When the world was explored by the Dawn probe, the great surprise were the bright spots, which turned out to be salt deposits left behind by briny water venting into space. The water comes from a substantial reservoir in the little world's interior. Two surprises in one - cryovolcanism closer than Jupiter's moons, and persistent liquid water in the asteroid belt. The belief is there is enough radioactive heavy stuff in Ceres' partially differentiated core to keep the water flowing (plus the water is briny, which lowers the freezing point). As an aside, how come it is reasonable to think Ceres is warm and active volcanically, while our much much larger Moon is considered too cold for ongoing volcanic activity? Here is the crater Occator and its dramatic salt fields: Ceres has more dramatic volcanic activity than Occator. It has the tallest mud volcano in the Solar System, Ahuna Mons! Earth, the only other world I know of with mud volcanoes, tends to have flat mud volcanoes because of its stronger gravity. But in the 0.03g of Ceres, the mud can pile high. Ahuna Mons is 4.1 km high and is unrivalled on Ceres. But there are many smaller mountains (called tholi) that may have been giant mudpiles like Ahuna but have slowly subsided back into the surface since their volcanism ceased. Aside from craters, saltpans and volcanoes, Ceres also has mysterious grooves (catenae): Ceres has been wet and rich in clay for billions of years. Not only is it a great world to explore for signs of life, due to it's small size and primordial nature, Ceres might have the oldest life in the Solar System!

Anyone?

The rays of Tycho run straight and true... But the rays of Copernicus and Kepler are wavy: I don't understand the difference. Does anyone know the reason why?

Thanks for the tutorials - I haven’t had time to go in details with them yet, but I have been looking for a Gimp Astro tutorial for years.

A Beelink SER6 Pro - this mini PC is actually my partner's new travel workstation, but the astro possibilities are tantalizing! Also an Intenso 3TB external drive, required for those huge solar system .SER files.

At least you can suntan at night 🙃

I've been playing with JMARS tonight - it is a mapping tool from NASA that shows projections of satellite imagery for many solar system bodies. You can then export the data as high resolution imagery. It can also make 3D projections of heightmaps with control of lighting, viewing angle and so on. Here's an export of Aristarchus - I do wonder why all the glass beads from the impact didn't scatter like the typical Copernican crater.

I am trying to shoot every day of the this lunar cycle (I've already missed one day though). Tonight the there was solid cloud but I figured some imaging was viable in the brief patches of slightly thinner cloud. I had to up the gain fourfold (16 times brighter in linear terms) and also quadrupled the length of my subs to 20 ms, so not a lot of light was getting through the clouds. In processing I had to shift the black point to the right to subtract the cloudglow.

Instantly recognizable!

My 90 mm frac is not best suited to a close-up competition, but here is my entry - this is about as close as I can get.

I have been pondering this for my small refractors, and the solution I am currently saving for is the Svbony 3-8 zoom.

I use a Wratten #8 when viewing planets at lower elevations - it significantly reduces atmospheric dispersion.

So methodical - respect!

According to my family reviews, "the bit at the bottom is good". Processed only in GIMP - I am finding the results from Registax to be a bit artificial.