From my home on the west bank of the Columbia River in Richland, Washington (46.3°N latitude), I have an unobstructed view of the sunrise along the east bank during an entire year. As a retirement project after a career of teaching and research in physics, I decided to take photographs of the sunrise for a year and, and at the same time, carry out…

The camera obscura is a well-known optical device in the form of a closed box with a hole in one of its walls through which light rays pass, forming an inverted image of the external objects on the opposite wall, as can be seen in Fig. 1(a). Despite the simplicity of its basic design, they have been widely used by scientists and artists. In…

We demonstrated that an optimally designed pinhole camera can be used as an astronomical tool to observe the libration and apparent diameter change of the Moon at night. The libration and apparent diameter change of the Moon were observed using a handmade pinhole camera with a diameter of 0.65 mm and a focal length of 400 mm. It was found that the…

Space telescopes are some of the most precise and complicated machines ever built. Not only must they survive the harshness of space travel, but they also need to be incredibly accurate: misalignments by fractions of a millimetre can have huge effects on the quality of the images they capture. In 1990, the Hubble Space Telescope became the first…

The purpose of this article is to provide teachers of science scientific definitions and illustrations to facilitate the teaching of cosmology. Secondary school science teachers can use the illustrations and their citations to pose questions to their students and to guide their students to accessible digital sites where the students can explore…

Recent solar eclipses provide relevant real-world contexts for learning about the scientific phenomena of the lunar phases. News coverage of the phenomenon may have raised questions such as, "Why does the Moon look different at different times, and sometimes as if it is not there?," and "What patterns can be found in the lunar…

Physics teachers are sometimes asked to teach an astronomy course for non-majors. One can't make that class dance and sing without the starry night, but on a brightly lit campus viewing deep sky objects may seem impossible. Hence instructors often opt for planetarium shows. However: 1) Planetariums aren't the real thing. 2) People living in large…

We study the variation of the apparent weight of an object with height above the surface of a planet with a (buoyant) atmosphere. Interestingly, this variation depends on two competing factors--the reduced gravitational acceleration (which acts to reduce the weight with increasing height) and the reduced buoyancy force in the progressively less…

The Sun does not return to the same position in the sky every 24 hours. At local noon, for example, the Sun will appear higher in the sky as we move from winter to summer solstice. In addition, and perhaps more surprisingly, solar days (the roughly 24 hours between subsequent local noons) vary in length, causing the Sun to be east or west of its…

The topic of the seasons is covered in both primary and secondary schools in Australia. It may be difficult for some students to comprehend how the Sun alters its position throughout the year. This article shows how to calculate the changing rising and setting positions of the Sun for one's locality and the extremes of its elevation near noon over…

Even though many physics teachers take their students on a calculation adventure through circular motion and Newton's universal law of gravity to determine Earth's velocity, most of us leave it at that. We present the final result and say, "Look, Earth is moving around the Sun at about 107,000 km/hr (66,000 mph), yet we can't feel the motion…

Laboratory astrophysics and astrochemistry are emerging fields highlighting the importance of laboratory simulations and experiments to benefit remote observations. In particular, ice mixtures found in the outer solar system may offer insight into the early evolution of organic molecules. H[subscript 2]O-ice mixtures containing other species such…

The Double Asteroid Redirection Test (DART) is a National Aeronautics and Space Administration--European Space Agency collaborative mission to test the feasibility of defending Earth from a catastrophic asteroid impact by using a spacecraft to deflect the asteroid away from the planet. Launched on Nov. 23, 2021, the DART spacecraft will intercept…

A solar eclipse provides a well-characterized reduction in solar radiation. Solar radiation is a driving factor in meteorological and climate models. Hence, solar eclipses provide a unique opportunity to do large-scale meteorological experiments by measuring the effects on temperature, pressure, and wind while the atmospheric conditions stay…

The concept of redshift is very often used in teaching physics and astronomy, as well as in science public outreach. Redshift is an interesting topic, used to describe many physical processes such as the Doppler effect or the expansion of the universe. Nevertheless, there are unfortunately also misconceptions about redshift. When facing the…