There are only three moons in the inner Solar System – Earth's Moon and the two orbiting Mars. But unlike our Moon, Mars' moons are much smaller and oddly shaped, resembling lumpy rocks rather than round spheres. Phobos, the larger of the two, is slowly spiralling towards Mars at a rate of about 1.8m every 100 years. In around 50 million years, it could either crash into the planet or break apart, forming a ring of debris around it. Meanwhile, the smaller and more distant Deimos is gradually drifting away. One of the biggest mysteries surrounding these moons is how they formed. CNA's Julie Yoo explores the leading theories. Read more: https://cna.asia/3UzlrNK Subscribe to our channel here: https://cna.asia/youtubesub Visit our website: https://cna.asia Download our app: https://cna.asia/app Get our editors' picks of stories via chat apps: Telegram: https://cna.asia/telegram WhatsApp: https://cna.asia/whatsapp Follow us on these platforms: https://www.facebook.com/channelnewsasia https://www.instagram.com/channelnewsasia https://www.tiktok.com/@channelnewsasia