Astronomy Picture of the Day<p>APOD from 2025-04-13</p><p>An Unusual Hole in <a href="https://mastodon.bot/tags/Mars" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Mars</span></a></p><p>Numerous holes dot Mars' Swiss cheese-like terrain, but one unusual 100m-wide hole seems to lead to a lower level. Possibly formed by a <a href="https://mastodon.bot/tags/meteor" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>meteor</span></a> impact, such openings may offer access to underground caves, potentially harboring Martian life and becoming prime exploration targets for future missions.</p><p>HD image at <a href="https://apod.nasa.gov/apod/ap250413.html#space" rel="nofollow noopener noreferrer" target="_blank"><span class="invisible">https://</span><span class="ellipsis">apod.nasa.gov/apod/ap250413.ht</span><span class="invisible">ml#space</span></a> <a href="https://mastodon.bot/tags/astronomy" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>astronomy</span></a></p>