![]() ![]() Check Heavens Above for local flyby times (Tip: Click on Tiangong.) Observers in the USA are favored this week with a series of bright passes in the pre-dawn sky. It's almost as bright as the planet Mars. In little more than 18 months, Tiangong has expanded from a small core barely able to fit a crew of three astronauts to a roomy, modern facility as large as Russia's Mir space station from the 1980s. He put together a composite of photos he has taken to show its rapid growth: Smith has been monitoring Tiangong since China started building the space station in April 2021. "The space station has changed shape since I last saw it," says Smith. 8th, Tiangong flew over Manorville, New York, where amateur astronomer Philip Smith was waiting with his backyard telescope: Its addition almost doubled the volume of the station, giving China a major outpost in Earth orbit. 31st when an 18-meter lab module named Mengtian ("Dreaming of the Heavens") reached orbit. Solar flare alerts: SMS TextĬHINA'S SPACE STATION IS COMPLETE: China has just completed construction of the Tiangong space station. Any explosions today (NOAA says there is a 15% chance) will be geoeffective as the sunspot is directly facing Earth. Big sunspot AR3141 has a 'beta-gamma' magnetic field that habors energy for strong M-class solar flares. QUIET WITH A CHANCE OF FLARES: Solar activiy is low, but the quiet could be short-lived. Neutron counts from the University of Oulu's Sodankyla Geophysical Observatory show that cosmic rays reaching Earth are slowly declining-a result of the yin-yang relationship between the solar cycle and cosmic rays. Credit: SDO/HMIĬosmic Rays Solar Cycle 25 is beginning, and this is reflected in the number of cosmic rays entering Earth's atmosphere. Since hail can cause the rainfall estimates to be higher than what is actually occurring, steps are taken to prevent these high dBZ values from being converted to rainfall.Sunspot AR3141 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Hail is a good reflector of energy and will return very high dBZ values. These values are estimates of the rainfall per hour, updated each volume scan, with rainfall accumulated over time. Depending on the type of weather occurring and the area of the U.S., forecasters use a set of rainrates which are associated to the dBZ values. The higher the dBZ, the stronger the rainrate. Typically, light rain is occurring when the dBZ value reaches 20. The scale of dBZ values is also related to the intensity of rainfall. The value of the dBZ depends upon the mode the radar is in at the time the image was created. Notice the color on each scale remains the same in both operational modes, only the values change. The other scale (near left) represents dBZ values when the radar is in precipitation mode (dBZ values from 5 to 75). One scale (far left) represents dBZ values when the radar is in clear air mode (dBZ values from -28 to +28). Each reflectivity image you see includes one of two color scales. ![]() The dBZ values increase as the strength of the signal returned to the radar increases. So, a more convenient number for calculations and comparison, a decibel (or logarithmic) scale (dBZ), is used. Reflectivity (designated by the letter Z) covers a wide range of signals (from very weak to very strong). "Reflectivity" is the amount of transmitted power returned to the radar receiver. The colors are the different echo intensities (reflectivity) measured in dBZ (decibels of Z) during each elevation scan. ![]()
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