M101 — The Pinwheel Galaxy

• Grasslands were spreading across continents; C₄ grasses were on the rise and reshaping ecosystems.
• Early apes such as Proconsul climbed trees in East Africa. The human lineage was still millions of years in the future.
• The Mediterranean looked nothing like today's sea — broad land bridges and shifting basins still separated Europe from Africa.
• Megalodon ruled the oceans. The Himalayas and Rockies were still actively growing taller.
• Global climate ran warmer than today, with forests reaching far higher latitudes than they do now.

The galaxy in the frame is a time capsule. The backyard, the mount, and the sensor are the receiving end of a message that has been in transit since before the Grand Canyon finished cutting downward.

By the numbers (integration set)

A few facts from the M 101 integration set behind this image:

• 108 light frames at 300 seconds each — about 9 hours of total exposure, gathered across two runs (June 13–14 and June 16–17, 2026).
• Calibration library: 80 bias, 40 dark, and 50 flat frames — roughly 2.4× as many calibration frames as lights.
• Sensor held near −10 °C through the marathon; filenames record gain 100, Bin 1.
• The set weighs in at 446 files / ~60 GB, including two stacked intermediates (stack-1 and stack-2) before the final export.
• M101 itself spans about 170,000 light-years — nearly twice the Milky Way's diameter — making it one of the largest and brightest spirals in the Messier catalog.

If you're counting photons: each 50 MB frame is a small brick in a very large wall of light that crossed intergalactic space for longer than hominins have existed.