Radio astronomers confirm Huygens entry in the atmosphere of Titan

At 11:25 CET the Robert C. Byrd Green Bank Telescope (GBT) of the National Radio-astronomy Observatory in West Virginia, USA, a part of the global network of radio telescopes involved in tracking the Huygens Titan probe, has detected the probe's 'carrier' (tone) signal.

14 January 2005

The detection occurred between 11:20 and 11:25 CET, shortly after the probe began its parachute descent through Titan's atmosphere. The extremely feeble signal was first picked up by the Radio Science Receiver supplied by the NASA Jet Propulsion Laboratory. This signal is an important indication that the Huygens probe is 'alive'. However, it does not contain yet any substance; the latter is expected to come a few hours later via the Cassini spacecraft.
What the Green Bank radio telescope has detected is only a ‘carrier’ signal. It indicates that the back cover of Huygens must have been ejected, the main parachute must have been deployed and that the probe has begun to transmit, in other words, the probe is ‘alive’. This, however, still does not mean that any data have been acquired, nor that they have been received by Cassini. The carrier signal is sent continuously throughout the descent and as such does not contain any scientific data. It is similar to the tone signal heard in a telephone handset once the latter is picked up.

Only after having received the data packets at ESOC will it be possible to say with certainty whether data were properly acquired. The first data set from Cassini will reach ESOC in the afternoon. Additional downlinks will follow throughout the evening and night for redundancy.

Further analysis of the signals will be conducted using other three independent data acquisition systems at the Green Bank Telescope. In addition to the GBT, sixteen other radio telescopes in Australia, China, Japan and the USA are involved in tracking the Huygens probe.

The ultimate goal of the tracking experiment is to reconstruct the probe's descent trajectory with an unprecedented accuracy of the order of one kilometre. The measurements will be conducted using Very Long Baseline Interferometry (VLBI) and Doppler tracking techniques. This would enable studies of the dynamics of Titan's atmosphere, which is considered to be a 'frozen' copy of that of the early Earth.

The VLBI component of the tracking experiment is coordinated by the Joint Institute for VLBI in Europe (JIVE) and ESA; the Doppler measurements are conducted by the Jet Propulsion Laboratory.

Radio astronomers confirm Huygens entry in the atmosphere of Titan

　次へ 　前へ

地震・天文11掲示板へ

フォローアップ:

• タイタンの地表に河川や氷…探査機が画像を初送信【読売新聞→ヤフーニュース】画像２つ有り 名無しＢ 2005/1/15 15:39:13 (1)
  • メタンの海？　ＥＳＡがタイタンの新たな画像公表【朝日新聞】メタンのもやが漂うオレンジ色の世界 エイドリアン 2005/1/16 15:54:31 (0)

　

　

　

拍手はせず、拍手一覧を見る

---

★登録無しでコメント可能。今すぐ反映　通常 ｜動画・ツイッター等 ｜htmltag可（熟練者向）
（タグCheck ｜タグに'だけを使っている場合のcheck ｜checkしない）（各説明）

（←ペンネーム新規登録ならチェック）
↓ペンネーム（2023/11/26から必須）

↓パスワード（ペンネームに必須）

（ペンネームとパスワードは初回使用で記録、次回以降にチェック。パスワードはメモすべし。）
↓画像認証
（ 上画像文字を入力）
ルール確認＆失敗対策
画像の URL (任意):

投稿コメント全ログ 　コメント即時配信 　スレ建て依頼 　削除コメント確認方法

---

★阿修羅♪　http://www.asyura2.com/ 　since 1995
　題名には必ず「阿修羅さんへ」と記述してください。
掲示板,ＭＬを含むこのサイトすべての
一切の引用、転載、リンクを許可いたします。確認メールは不要です。
引用元リンクを表示してください。