As part of the Tianwen-1 mission, the Zhurong rover successfully touched down in southern Utopia Planitia on 15 May 2021. On the basis of the new sub-metre-resolution images from the High Resolution Imaging Camera on board the Tianwen-1 orbiter, we determined that the Zhurong rover landed at 109.925° E, 25.066° N at an elevation of −4,099.4 m. The landing site is near the highland–lowland boundary1 and multiple suspected shorelines2–7. Under the guidance of the remote sensing survey, the Zhurong rover is travelling south for specific in situ investigation. Supported by the six payloads on board the rover8, its initial key targets are rocks, rocky fields, transverse aeolian ridges and subsurface structures along the path. Extended investigation will aim at troughs and cones in the distance. A better understanding of the formation mechanisms of these targets may shed light on the historical volcanism and water/ice activities within the landing area, as well as the activities of the wind. These results may reveal the characteristics and evolution of the ancient Martian environment and advance the exploration of the habitability of ancient Mars.

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The global lunar image of the first phase of Chinese Lunar Exploration Program is the first image that covered all over the surface of the Moon. It will serve as a critical foundation for succeeding exploration and scientific research. In this paper, the acquisition, characteristics, and data quality of Chang'E-1 CCD image data are described in detail. Also described are the methodology and procedure of data processing. According to rule of planetary cartography, the image data have been processed, geometrically corrected, and then mosaicked and merged in a scale of 1:2.5 million. The results of data processing and charting show that the image data of Chang'E-1 CCD and their geometric precision meet the demand of charting a map in the scale of 1:2.5 million. The relative geometric positioning precision of the global image is better than 240 m, and the absolute geometric positioning precision is slightly better than that of the ULCN2005 and Clementine lunar basemap (V2.0). The plane positioning precision is approximately 100-1500 m. This global image proves to be the best global image of the Moon so far in terms of space coverage, image quality, and positioning precision.Chang'E-1, lunar CCD data processing, lunar image position, lunar global image Citation:Li C L, Liu J J, Ren X, et al. The global image of the Moon obtained by the Chang'E-1: Data processing and lunar cartography.

China’s first Mars exploration mission (HuoXing-1) has been named as ‘Tianwen-1’ meaning Heaven Inquiry. Tianwen-1 was launched on July 23, 2020. In this paper, the scientific objectives of earlier and current Mars exploration missions worldwide are reviewed, and the scientific objectives, payloads and preliminary scientific investigation plan of China’s first Mars exploration mission are introduced, and expected scientific achievements are analyzed.

The Laser AltiMeter (LAM), as one of the main payloads of Chang'E-1 probe, is used to measure the topography of the lunar surface. It performed the first measurement at 02:22 on November 28th, 2007. Up to December 4th 2008, the total number of measurements was approximately 9.12 million, covering the whole surface of the Moon. Using the LAM data, we constructed a global lunar Digtal Elevation Model (DEM) with 3 km spatial resolution. The model shows pronounced morphological characteristics, legible and vivid details of the lunar surface. The plane positioning accuracy of the DEM is 445 m (1σ), and the vertical accuracy is 60 m (1σ). From this DEM model, we measured the full range of the altitude difference on the lunar surface, which is about 19.807 km. The highest point is 10.629 km high, on a peak between crater Korolev and crater Dirichlet-Jackson at (158.656°W, 5.441°N) and the lowest point is −9.178 km in height, inside crater Antoniadi (172.413°W, 70.368°S) in the South Pole-Aitken Basin. By comparison, the DEM model of Chang'E-1 is better than the USA ULCN2005 in accuracy and resolution and is probably identical to the DEM of Japan SELENE, but the DEM of Chang'E-1 reveals a new lowest point, clearly lower than that of SELENE.Chang'E-1, laser altimetry, lunar DEM, topographic tops of the Moon Citation:Li C L, Ren X, Liu J J, et al. Laser altimetry data of Chang'E-1 and the global lunar DEM model.

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A new calibration model of a radio telescope that includes pointing error is presented, which considers nonlinear errors in the azimuth axis. For a large radio telescope, in particular for a telescope with a turntable, it is difficult to correct pointing errors using a traditional linear calibration model, because errors produced by the wheel-on-rail or center bearing structures are generally nonlinear. Fourier expansion is made for the oblique error and parameters describing the inclination direction along the azimuth axis based on the linear calibration model, and a new calibration model for pointing is derived. The new pointing model is applied to the 40m radio telescope administered by Yunnan Observatories, which is a telescope that uses a turntable. The results show that this model can significantly reduce the residual systematic errors due to nonlinearity in the azimuth axis compared with the linear model.