query: How big should a lens of a telescope be so we can see the American flag on the Moon from the Earth's surface?
positive_passages.docid: 141902
positive_passages.text: Observing lunar lander and footprints on the moon?
negative_passages.docid: 40309
negative_passages.text: Glass acting as a lens?
negative_passages.docid: 9671
negative_passages.text: Do gravitational lenses have a focus point?
negative_passages.docid: 57449
negative_passages.text: TikZ: How to make a convex lens
negative_passages.docid: 34411
negative_passages.text: What lens characteristics are important in star photography?
negative_passages.docid: 113839
negative_passages.text: How can I visualize or simulate the effect of different focal lengths?
negative_passages.docid: 11996
negative_passages.text: How do I find the right size of filters for a lens?
negative_passages.docid: 6544
negative_passages.text: How do zoom lenses restrict their widest aperture at the telephoto end?
negative_passages.docid: 105692
negative_passages.text: Which compact camera to shoot stars, moon and hopefully planets and sun?
negative_passages.docid: 83556
negative_passages.text: What are the theoretical minimum and maximum apertures?
negative_passages.docid: 85812
negative_passages.text: Are mirror lenses good for wildlife photography in daylight?
negative_passages.docid: 85095
negative_passages.text: Selecting optical size?
negative_passages.docid: 11926
negative_passages.text: Earth-Moon system
negative_passages.docid: 53448
negative_passages.text: Do bigger focal lengths capture more light?
negative_passages.docid: 47620
negative_passages.text: How does a circular lens produce rectangular shots?
negative_passages.docid: 60690
negative_passages.text: Optical microscope magnification limits?
negative_passages.docid: 143419
negative_passages.text: A mirror in the sky to look at past Earth