“极目”眺望，“望”什么呢？
2020年12月10日4时14分，我国在西昌卫星发射中心用长征十一号运载火箭，以“一箭双星”方式将引力波暴高能电磁对应体全天监测器（GECAM）卫星送入预定轨道，发射获得圆满成功。
China sent two satellites for the detection of gravitational waves into planned orbit from Xichang Satellite Launch Center in southwest China's Sichuan Province on Thursday morning.
此次发射的两颗科学卫星全称叫引力波暴高能电磁对应体全天监测器，顾名思义，它的使命就是全天候监测引力波伽马暴，寻找引力波之光。
如果以水面来比喻时空，那么引力波就可以看作是时空的涟漪。在爱因斯坦1916年提出的广义相对论中，引力波被认为是由质量所引发的时空扭曲而成，任何有质量的物体在加速运动时都会对周围的时空产生影响。而这一作用形式就是所谓的引力波。
引力波暴高能电磁对应体全天监测器卫星由中国科学院战略性先导科技专项空间科学（二期）部署，正式命名为“怀柔一号”，研究人员还给卫星起了个昵称叫“极目”。“极目”望远镜，包括 “小极”和“小目”2颗小卫星。
The two satellites, with the Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission, were launched by a Long March-11 carrier rocket at 4:14 a.m. Beijing Time, according to the center.The GECAM project is being carried out by the Chinese Academy of Sciences.
According to Einstein's theory of general relativity, gravitational waves are ripples in the fabric of space – a stretching and squeezing of space itself. They are caused by some of the most violent phenomena in the universe, such as the supernova explosions that blast apart dying stars, and the collisions of neutron stars and black holes.
Collisions of two neutron stars or a neutron star with a black hole are astrophysical phenomena which are likely to generate gravitational waves that are strong enough to be detected on Earth. These cataclysmic events are also thought to be the cause of some brief flashes of very energetic gamma radiation that are observed from all parts of the sky.
中子星和黑洞等致密天体并合过程中会产生引力波，同时还会伴随高能辐射、伽马暴、磁星爆发及快速射电暴等等高能爆发现象，而这些爆发现象就是“极目”卫星的主要观测目标。“极目”卫星的观测数据，将推动破解黑洞、中子星等致密天体的形成和演化，以及双致密星并合之谜。