Excel 4.0 Workbook. .xlw. An Excel 4.0 file format that saves only worksheets, chart sheets, and macro sheets. You can open a workbook in this file format in Office Excel 2007, but you cannot save an Excel file to this file format.
According to scientists, the surface of Neptune is one of the coldest places in the Solar System. At its surface, where the clouds of the planet touch space, the temperature of Neptune can dip down to 55 Kelvin. Thatâs -218 degrees Celsius. Neptune and its Great Dark Spot.
1 The atmosphere of Neptune is made of hydrogen and helium, with some methane. The methane absorbs red light, which makes the planet appear a lovely blue. High, thin clouds drift in the upper atmosphere.  Neptune has a very active climate.